It's a matter of personal preference, but we always rent a car no matter where we stay, OKW or BWV. The busses are OK, but we prefer the car. We turn on the A/C and the radio and enjoy our trip back to the resort. If we want to stop somewhere in between, no problem. Don't have to wait, no worry about getting a seat. We only used the bus once when we stayed at OKW last month and that was to the MK at night when they were having Spectromagic & fireworks, we knew it would be crowded getting out and would be easier to just hop the bus outside MK and go straight back since it would be late.
We also like to go the outlets, use the car for grocery shopping, we had lunch or dinner a couple of times at Crossroads.
Even if you use a towncar service, you may need to get back to the grocery store during the week, with a car it's no problem. When you consider the cost of a shuttle or town car service, you aren't paying that much extra for the car. I paid $110 including tax last month for a full size from National with Disney Club & Entertainment discounts. Granted, you have to keep checking to get a good rate but I always manage to land one under $150.
When we stay at BWV, we take the boats or walk to Epcot & MGM, drive everywhere else except sometimes MK we take the bus.