Yes, I have rented one, and no they aren't hard to maneuver. The cost is $15 which includes the one dollar deposit per day, and when you return it with your pink slip you will receive one Disney Dollar back. Hold on to the pink ticket they give you, because if you leave one park and go to another, you can get a stroller there without paying again, in the same day. They are also now doing length of stay stroller rental. I think it saves you about one dollar a day in rental payment.
If you go to DTD, their stroller and w/c policy is quite different. They do not have double strollers, as they don't fit through the stores easily. Also, the rental is $7 per day for each single, with a $20 refundable deposit on each stroller or w/c rented, as it is an ungated property. They will honor the length of stay coupons, however, you will still have to pay the refundable deposit.