I'm working on the logistics for a trip to Spain next month; currently working on Barcelona.

I've just received my travel companion's wish list, and now I'm trying to figure out how much we can realistically fit into a day, how much time to allow for each attraction, and the most efficient way to tackle the items on the wish list. We'll be purchasing timed tickets for a few attractions, so we need to plan well.

We'll have four full days in Barcelona and two partial days. One full day will be dedicated to Monserrat. We're staying near Sagrada Familia, so we'll probably visit in the morning. Otherwise, I'm not sure how to organize the other sites.

The wish list:

Segrada Familia
Park Guell
Casa Batllo
Casa Milla
Basilica of Santa Maria del Mar
Barcelona Cathedral
National Art Museum
Paleu de Musica (possibly in conjunction with an evening guitar concert)
Hospital San Pau

I see that there is a Hop on Hop off bus, but I'm not clear if this is an efficient option. I'm a walker, my travel companion isn't, but sometimes it's faster to walk than to wait around for a bus.

Suggestions and thoughts greatly appreciated!

I'm fanatic about efficient trip planning, so you might want to look at my trip report.
Be sure to reserve the Sagrada Familia in advance, and consider reservations for the other Moderniste sites as well.
I doubt the HoHo would make much sense for you.

You aren't going to be walking from Sagrada Familia to the Miro museum, for example. All sites of interest are not in one central location within a half to one mile radius. I think you may not realize how big Barcelona is and how far apart some of those locations are. I think in Barcelona the hopon/off bus is extremely useful, except in the dense area near the cathedral. I picked it up near the Gaudi houses on psg de Gracia then took it to the Catalonian art museum, plaza de Espana, the Miro museum, etc, then it comes down near the water and I did finally ditch it around the cathedral where traffic gets bad. But I got almost a good day out of it. I did not use the hopon/off bus for Parc Guell but some people do, I used the regular bus system. You are not going to be walking there, I imagine. Maybe you should check a map on deciding some of these things. Some of your shorter distances are only a couple km, (over a mile), if that's okay with you, like the Pedrera to the Palau de la Musica. But you can't walk to the national art museum, and I bet you aren't going to walk from even those Gaudi houses to Parc Guell, and they are a bit of a hike from the area near the cathedral. etc. So I don't think it's an issue of walking versus thinking youll use the metro and bus systems. I think that isn't so easy to get up to national art museum (that bus also goes by the monastery). There isn't any metro stop near the Catalonian Art Museum, if you don't use the HOHO, I think you have to take the metro to placa d'espana and then a bus from there or something like that, you'd have to find out). But you'll have a plan a lot more of logistics for some of the farther out things, that's all. Barcelona is a big city with big, wide avenues in some areas, the bus isn't hampered by traffic that much at all out of the real core old quarter center. Plus, weather is usually pretty nice in Barcelona so you can have a nice excursion with good views from the top of that bus in Barcelona. You may end up spending more time in certain areas, like going out to the parc Montjuic area. It also has a line that goes near Parc Guell and Sant Pau. Otherwise, you can take the metro and a bus, or just take a bus which actually gets you closest like I did. I caught it somewhere along psg de Gracia I think it was bus 24. barcelona has a good public transportation website www.tmb.cat

You have plenty of time to see all that, and some things aren't even on your list that I really liked, anyway (like the Miro museum or the Maritime museum or the archeological museum, etc). You have a lot of Gaudi buildings, I wouldn't do so many of those to the exclusion of other things as he has a very distinctive style which isn't all that different in various buildings. The one that is kind of different you don't have on your list anyway (the house down near the Ramblas). The parc is different, it wasn't my favorite thing in Barcelona, and of course Sagrada Familia. I just think it might be overdose to visit both the Pedrera and Casa Batllo on the same day. I've been there a couple times so did those on different trips.

If you do the HOHO one day, I'd use it perhaps for the Catalonian Art Museum for sure (the Miro museum is out there if you care, it may not be to your taste as it's not on your list -- Picasso isn't either but I wasn't that crazy about the Picasso museum in Barcelona myself, so I'm with you on that one, you can see his stuff a lot in many cities), plus maybe parc Guell and Sant Pau. That would be full day.

Appreciate the feedback.

After some significant research I think I'm getting a handle on things.

IMO the Ho-Ho bus is a total waste of time and money. Barcelona has an excellent metro and bus system.
Don't miss the lesser known Casa Vicens (Gaudí's first house).

When thinking about Barcelona, it reminds me of LA, so spread out. We used the HoHo as transportation such as getting up on top of Montjuic to visit Olympic sites and Museo Miró, one of our favourite places.