I am finishing up a trip to Maui where I stayed at both properties and preferred the Ritz. The pools you mention are the 2 nearest the restaurant, not the large infinity adult pool or kids pools.
I am a Platinum and had booked the lowest level rooms at both properties. At the Ritz I was upgraded to a 1 Bedroom Residential Garden Suite and at the Wailea property I had a choice of a garden view suit or oceanfront room and took the oceanfront room. Both properties i arrived around 1 pm. My room was ready at the Ritz and had to wait till almost 4 at Wailea. If it is hot avoid building 7 at Wailea as the air conditioning does not work well. First room it turned off and second room can't get room below 74, even when set to 65. Spoke to someone else in same building with same problem.
I think the rate at the Ritz was only $20-30 more. Don't know how many nights you are staying but the Ritz is running a special till the end of the year where you pay for 4 nights and get 5th free plus breakfast included. If you use the AA rate at Ritz make sure you have a card as they will ask for it. Pool at the Ritz was large and open 24 hours and the water was cool. At Wailea pools are nice but close at 10 and like a bathtub.The fitness center at Wailea was nicer.
Beach closer at Wailea and if you have an ocean or view room at Wailea much closer to the ocean.
Wailea has the nice path along the beach to walk and more shops, restaurants, and other hotels to walk to. The shuttle at the Ritz was convenient to take to nearby beaches. Food and drinks at the Ritz was more expensive. Service at the Ritz was much more personalized. For instance I asked about having housekeeping service at a specific time at Wailea and was told they will come any time between 8 am and 12 noon vs at the Ritz I called and they were there within 15 minutes. Don't know what time of year you are going but the area around the Ritz tends to be windier, cooler, with more rain.
If you have any other questions let me know.