I think the first item you want is to have the 3 units close ( preferably in same villa complex - please make sure you request this asap with owners services ). Most villas have 3 levels ( some have 2 ) and many have the upper as a one bedroom unit - leaving the mid and lower floors with two 2 bedroom units ( or lock off to a 1 bedroom and a studio ). The studio's are very large .. so you can party in the friend's rooms as well...
I am confident you won't find a 'bad' unit. Some units appeal to some and less so for others ... example would be what level you are on and how you are handle stairs ( but since you said you can walk ...rule that out ) ... and stairs are only for one floor ( up or down ).
Another example of a 'weaker' unit might be ... in the Meadows many units back onto the pool area .. great for some and less so for others. The scenery from balconies is very nice - but over time you will develop your favourite views. 20 years an owner - think this will come to change once you stay here ...
and make this an annual event.
The fitness area's are smaller now and my wife meet people from the Meadows that came up to the Summit for Gym. But the Meadows has the new Spa and the Restaurant.
One point lost on many is to request the time you like maid service. Starts at 9:00 thru 4:00. Plan your time and activities to have this service as less of a disruption and more of a feature that is missed when you are back home. We smile at how many put up the do not disturb signs - they have not mastered the system to their max pleasure.
I can't think of many villa's that are far from a BBQ ( or the stand alone Washer Dryer rooms for the studio's ) ... you are typically spoiled here vs. compared to many high density time shares.
Speaking of walking ...a favourite walk is from the Meadows to Summit or visa versa ...the views are fantastic. Or need a lift - just call ( we always requested the golf carts vs the mini-van's - the choice as always if yours when at Aviara).
Enjoy
Greg