I asked here on the boards mid Feb and got no replies so I made one reservation with Fox for $34, another with Alamo for $70. I figured if I'm not happy, I'd just take the shuttle back to MCO and use the Alamo reservation. My dates were 2/27-3/1.
The shuttle arrived after a 10 minute wait. Had I used Alamo, I'd have been on my way out the airport by then.
The line at the counter took 15 minutes. By then I would have been at WDW.
The car was fabulous, returning not bad. I did have to wait for a shuttle back to the airport which made me antsy.
Conclusions: I would use Fox again under certain conditions.
1. I need to save enough money to make it worthwhile.
2. I would not use them if it cut into a park day. I arrived and departed at about 6pm and it didn't affect my day.
3. If you want an additional driver, it might not be worth it either.