expensive to rent at the parks; it's like $48/day, now. There are some rental companies that have a deal for $150/week plus tax. Now, they won't be as big as the ones at Disney, but they work just fine. For a little more you can get a bigger one. The big plus is that your always with one available when you rent from an outside place. At Disney it's first come; first serve.
There's more work with renting one because you need to get it in and out of your room. You need to use Disney transportation; unless, you have your own car. It's an adjustment learning to get a
scooter on and off the bus. You are responsible for recharging the battery.
It is nice to use the scooter at the resort especially if you plan on swimming or using the food courts. It's less tiring waiting for the buses, too.
We've done it both ways, but when the prices increased to $48/day we decided to rent from an outside source. We use Apple Scooters; we find them to be the most reasonable.