Hi Paula: Since I live here, I've never actually stayed at one so can't comment on the inside...but can on the location. Also, take a look at this link where some travelers rated both. They pretty much match my advice.
Basically, Bonaventure and the Vacation club are like little resorts in that there's plenty to do onsite - golfing, tennis, pools, spa.
The Mizner is located in a better spot because you have access to what we call our "Town Center" which has some shops, couple of restaurants, coffee shop, cheese/wine stop (this place is awesome by the way) and you are located right next door to a big grocery store. I know the Mizner has a pool and may have tennis courts...but not sure if they have more.
That said, the other two locations are only about 5 minutes away from the Town Center so you could choose that spot and still have access to the above items I listed -- you would just have to drive, rather than walk out your front door to access them.
Here's the link to the Weston Town Center so you can see what's there. It's about 30 steps away from the Mizner.