Barcelona has enough legitimate rental apartment businesses that you should avoid airbnb and homeaway.

Both the habitat and negre options are in decent locations. Habitat is reputable; no knowledge of Negre. Check to see if it's a member of APARTUR.

You need also to understand what you're looking at, and you seem not to. First: One of those homeaway apts has three reviews and two are crappy - why consider it? Second, you have two hobbits, which indicates you should have 2 bedrooms, not one. Apts are SMALL. Translate the room thus: 1 square meter = 10.6 square feet (actually, a little less). A 50 square meter apartment is < 530 square feet.

The biggest apartment you listed is the third one (80 m2) and it has TATAMIS for the bed and living room. If you're not accustomed to sleeping on the floor (Tatamis are traditional Japanese flooring and not used in newer abodes in Japan) or a near equivalent (think 1/2 inch foam mat), you will not be comfortable.

Good info! We don't mind a small apartment as long as it's not a studio. The kids are young...the baby usually ends up in our bed anyhow and a mat or pull out sofa is fine for our three year old. The only reason I went to airbnb and homeaway was to try and find something a bit cheaper. Have you heard of barcelonacheckin.com?

Don't recall it. Looked at a ton of apts before we settled on one from barcelonastuff.com.

I was traveled to Barcelona in January with my boyfriend and sister, and we stayed at a wonderful 2 bedroom apartment on Carrer Princesa through the Chic & Basic Born Apartments, the office was down the street and had free water and coffee during the day. The only issue was the tiny elevator, which is normal for Europe, but could be an inconvenience with four plus luggage, and the stairwell was really dark, so we usually took the small elevator. The apartment was about $120 total, and had 2 separate bedrooms, one with a double and the other with 2 singles, plus a living area, dining/kitchen, and bathroom. Excellent location!! We loved it.

the sec .one is a good location and high floor ( less noise)

With two little kids (and stroller?) and grocery shopping planned, I would look for one with an elevator.
Have not scanned all apartments, but I think only one mentioned it explicitely.

Yes, a lift would be good. Or if no lift, then an apartment on the ground of first floor. Ok...I'm leaning toward http://negre.us/apartments/Valencia/32/, but it's still a bit out of our price budget. I guess I'll go back to the drawing board.

As with any property, location is a key factor.

If you expect to be able to walk to most tourist sights, you should focus on the Old Town/Barri Gotic, Born & Ribeira or the lower central Eixample district (roughly an area bordered by Universitat, Passeig de Gràcia, Urquinaona and Pl. Catalunya metro stops. Like the apartment #5 of your list.

If apartments in these areas are not within your budget and you have to consider one where the use of public transport will be more or less a must, then you can economize by staying elsewhere as long as you are within short walking distance to a metro stop that got lifts (for strollers etc.)

At that point, it does not really matter that much where you will stay, travel-timewise so to speak. As it takes a while to get down to the platforms (wait for elevators etc.), the actual time you need to get from street level to street level is more or less the same if you ride 1 or 5 stops, 10 vs 15 minutes.

Not all locations that require a metro ride to Pl. Catalunya are worse than the more centrally located. Many are actually very fine residential neighborhoods which give you more value for money than the more popular "close to Pl. Catalunya" locations.
Gràcia, for example, has a very distinctive flair of a small town which got surrounded by Barcelona during the last century. You have your own infrastructure of a decent shopping mile, supermarkets, pittoresque squares dotted with cafes and restaurants. But still only 3 metro stops to the bustling city center.

I stayed in the Negre apartment about 3 years ago. There were 2 of us -- both retired ladies -- so it worked well for us.

The Negre company was very reliable and hospitable. My cousin had also used them the previous year and recommended them. The location is decent -- in the Eixample. We found the apartment charming and very well kept. The best feature was a glass-enclosed sun-room across one end of the apartment which looked out into the large open core of the entire city block. The table is in the sun-room, so we had breakfast there each day.

However, I am not certain this apartment would work for your family.

Details: Pros: The larger bedroom is light and airy and connects via double doors to the living room and to the sun-room. The living room is roomy and comfortable. The kitchen is larger than most and had a full-sized refrigerator.

Cons: The bathroom tub/shower was a small tub about 2.5 feet by 3 feet. The smaller bedroom has a single twin bed and was rather dark, with only a window on an air-shaft.

I hope you enjoy Barcelona as much as we did.

I was between these two apt and finally got UP Suites through Booking.com for a very good price

http://www.upsuitesbcn.com/apartamento_suite.php

Bonavista Suites in Gracia is also a great place and location, both 9 in ratings.

http://www.flipkey.com/barcelona-condo-rentals/p317103/

Regarding option above http://negre.us/apartments/Valencia/32 :
- Location is good
- Girona Metro station nearby
- The Mercado Conceptual is close by which is a big plus
- There is a Rotisserie Chicken place across from the mercado
- There is a Health Food store further down Carrier D'Argo (15min walk)
Downside of this apartment is the small bath tub and busy street/traffic but this is common anywhere in Barcelona.

Have you tried Friendly Rentals. I booked with them for my San Sebastian trip last October and had no issues. I know they are reputable.

I'll look into Friendly Rentals. I don't know if I've gone to their site. It seems like I've looked at hundreds! Small tub is okay. At least it has a tub. A lot of places only have a shower and that is hard to manage with two small kids. I'll just have to wash them one at a time if I take the Negre apartment! Street traffic kinda sucks, but beggars can't be choosers right? I'm trying to get a good budget apartment. We're pretty cheap. Thanks for the tips!

What about this one?

http://www.friendlyrentals.com/en/apartments/barcelona/apartment-2498-1.htm

I can relate when you say 'hundreds'.

When I choose an apartment I take all the reviews into consideration and have 3 top criteria's - location, internet and washing machine. Budget is a big factor but any major city will be expensive. Barcelona is no exception. Apartment 2498 sounds good. I also found The Dahl Apartment in Barcelona - 1 bed, standard.
If you want to see actual pictures of the apartment street location, click on the LOCATION of the apartment. There will be a pop up icon of the exact location and it will ask you 'How to arrive'. Click on this link and it will take you to Goggle maps. Click on the same icon in Goggle maps and you will see an option 'Street View' which shows you the actual street pics. You can also click and drag up and down the street. This at least gives you an idea on what the location looks like. Anyhow, I don't thing you can go wrong if you stay in the Exiample area (south of the Avinguda Diagonal - closer to the major attractions).

Also check out websites Slowtrav or Tripadvisor to see if these apartments have been posted or just to read up on apartment reviews. I know this is a lot of work and stressful but sometimes you just have to go with your gut and pick one.

Tips on saving money is to pack some amenities with you. Example, peanut butter, jam, instant oatmeal, nuts, granola bars, dish soap, laundry soap, tea, bar soap. You may not have room in your suitcase since you have children's things to bring.

Let us know what you end up with. Good luck!

The location is very central.