You can't go wrong with any of the resorts, so its hard to say which is best. I have stayed at the Sea World location and Tuscany.
Sea World:
--Plenty of parking.
--Easy freeway in and out access on I-4 for Disney. However, there is no southbound exit if you are coming from Universal, so some surface street driving will be required when returning from Universal.
--You can walk to Sea World. There are also some minor perks from the resort for Sea World.
Tuscany:
--Grocery shopping, Outback Steakhouse, Walgreens, etc. are across the street from the resort.
--Outlet shopping is just around the bend. Its possible to walk there.
--Parking can be an issue late at night. One night we had to park near the clubhouse and walk back to our condo. It was only about 10 p.m., and the parking outside the units was full.
I haven't tried the restaurants or bars at either resort.
I don't think the differences between the resorts are all that significant when you are looking for a place for two adults.