My husband and I are planning a trip to Maui for our anniversary.(no kids). We are having trouble deciding on which resort area to stay at - Kanapalli or Wailea. The hotels we are thinking about are either the The Westin Maui in Kanapalli or the Grand Wailea.

Well, I'll bite ! Not stayed at either property itself but I suggest the first decision might be in which area to stay, then narrow down the choice of digs. Depends too upon what you like to do on vac. Kaanapali is busy, has a nice beach, Whalers Village etc. Wailea is, I'm told, a bit quieter. On our last trip we even wondered whether we'd like to split a vacation between the two areas as the beaches down by Wailea (and beyond) seem more open and uncrowded, but there's more choices re restaurants etc up in Lahaina and north.
There, that should stir it up !
For the two areas, based on reports and observations, I'd look at The Whaler (I like a condo)/ Kaanapali Alii - if feeling flush, or Renaissance Wailea (no experience with condos down there, but lots good reviews for the hotel). That's my current target list for possible future trips.
In reality, you'll have a great time whichever you choose, it's a wonderful place to take a vacation.
Cheers

Grand Wailea is a true luxury resort hotel.
The Westin is outdated and not even close to being as nice.
No real comparison between these two.

First off, are you checking the island out or hanging at the pool? If you want to really enjoy the island then stay both areas. We like to split the areas to fully enjoy them. For us we stay cheap in Kanapalli and adventure out. Then we settle in Wailea and relax with trips to Makena, close to home.

Where do you "stay cheap" in Kaanapali ??

I guess I should have provided more info. We are looking to go to Maui in Nov-Dec. We are planning on visting Ohau first to do all the "touristy" things then we were thinking on going to Maui for about 3-4 days to relax. Reading the reviews from others it seems like Kanapalli is the "action" place and Wailea is more peaceful. Is this true? Are both areas the same in the weather dept? I like a "poshy" resort with a nice pool area and beach (and a little bit of pampering wouldn't hurt). We are active folks and like to do walks and runs along the beaches.

You're describing the Grand Wailea, and definitely not the Westin.

It definitely sounds like the Grand Wailea is the place for you. You should try to go up to Ka'anapali for the nightlife/restaurants/shops, etc though.

On the subject of Oahu, I was only in the the Honolulu airport, but I would not waste more than 1-2 nights on Oahu. That way you can acclimate to the time change and see Pearl Harbor and the USS Arizona. Otherwise, Honolulu seems like a large city in a tropical setting. You can see waterfalls, and do Haleakala, Hana, and so much more on Maui (and since you will be there in Nov-Dec, I would recommend doing a whale-watching cruise).

Best of luck and enjoy HI; it will be wonderful no matter where you decide to stay!

Sounds like the last poster didn't like the Honolulu airport !

We were on both islands in June, and regarding Maui, the one regret I had, was that we stayed by Kaanapali instead of Wailea. We checked out Wailea before leaving for home, and loved the area.
I don't know how long you're spending on Oahu, but we loved the island. We did not stay in Waikiki, which may explain why we enjoyed it so much. We stayed at the Ihalani, about a half hour away, and did trips around the whole island. There are so many beautiful beaches away from the crowds. I'd recommend doing that, if time allows.

I've stayed at the Westin and the Kea Lani. The Kea Lani is very near to the Grand Wailea, and I highly recommend it! The Westin is nice, and I had a great time there. The pool is huge, the rooms small, and the service fine. There is a great jogging path there, and I love the Kanapalli area. But, the Kea Lani was even better! The Grand Wailea sits on a great beach, it is much nicer than the Westin, and their pool area is really really something else. We thought the Kea Lani was the best hotel we have ever stayed at. There are plenty of great resturents in Waliea. I'd choose the Grand Wailea or the Kea Lani. The Wailea area is newer and nicer, but the Kanapalli area is still very nice. You can't go wrong.

Well, after thinking this over, we have decided on going with Wailea or Kanapalli. It seems to be what we are looking for. We chose the Grand Wailea resort. They have a special on their website. For every 2 nights you pay for, you get a third night free. I appreciate all those who replied. Your responses helped!