From a vacation home point of view :
Having lived on the west side for 4 years I can say that it is generally a quieter area than the east side. Some excellent restaurants are in the Formosa Gardens shopping area. Access to Disney, partic. if you use the backroads, is easier.
Vacation Home developments to west :
Sunset Lakes, Lindfields, Rolling Hills, Indian Creek, Wyndham Palms, Indian Ridge Oaks, Indian Ridge are all within 10 mins of Disney. If you use the backroads you can be there quicker.
I now live on the East side and I can say that access to Disney is a little longer. The East side is more popular with people who have been coming to the area for many years probably because they are familar with it. To get to Disney you can either go along US 192 or via Buenaventura/US 535. Again excellent restauarants exist so no real difference there. The main advantage of the East side at the moment is access to the superstores and the main shops...
Walmart, Target etc. If you are on the west it will take 20 mins to get to Walmart...on the east 4 or 5 mins but very often quicker. Access to I-Drive is also easier.
Vacation Home development to east:
Cumbrian Lakes, Indian Point, Eagle Pointe, Lake Berkley are all within 10-15 mins drive of WDW.