We used GMS last week due to the recommendation here. My husband threw his back out right before the trip.
They were great! Got our package with all the info and the day before they texted me regarding the drop off time. I stated the time we should be arriving but if we were delayed I would let him know. Got another text on arrival day asking if we were on time, which I verified. He even texted me to let me know he would be there in 10 minutes. I also had the guy from Connecticut (that is where we are from), he was awesome, gave my husband instructions and showed him where everything was. Even gave him the tip that if you get back on and try to move and all you hear is the beep beep beep...the main reason is that a cast member may have moved the ECV and not taken it out of neutral. He said that is their main calls. Also this thing went forever on one charge. We forgot to charge it one night and it still was a full charge.
We received texts the next day asking if everything was ok and if there was anything questions we had. And as for drop off, we got a text confirmation of the time and place and another when he was on route.
I would totally recommend this to anyone. This was my first need of an ECV and if this is the service we received, I am now spoiled...