More and more last minute calls are coming in for scooter rentals. Walt Disney World has raised their prices for a daily in-park scooter rental to $70 a day (includes $20 key deposit that you get back) and reports from customers are they are still running out first thing in the morning. So if you are planning to rent a scooter at the park you either need to get to Disney first thing and get in line at the park you are visiting or renting a scooter like you might do a car and using it at your hotel or resort, all the theme parks including getting to and from either your car or buses, monorail, boats etc. If you do decide to rent your own scooter to use during your visit you need to consider if you are staying on-property or off. If you are off-property, make sure you rent one of the newer advanced technology scooters that are truly lightweight and easily disassemble and will fit in a car trunk.
If you are staying on-property, consider whether you might ever want to take your scooter to a different location such as a mall, another theme park, a restaurant or perhaps decide to use a car, taxi or shuttle service rather than waiting for on-property transportation (maybe your running late and would like to just get there sooner by car or taxi). If you MIGHT want to use alternative transportation and take your scooter with you, go for a transportable model, but if not, consider a fun specially outfitted on-property model.
Ensure you rent from a company that is very informative on their website, has long telephone/office service hours, commits to repair and replacement, will service you inside a theme park and finally offers detailed video clips of each model so you can make the best informed decision.