Reservation rides observations (at least for my area):
1. The pay is for the shortest possible distance and the time is based on no traffic delays. After you start the trip immediately screen shot the overview map. Wait a few seconds and screen shot it again. Uber will change the routing to the quickest way, which may include more miles and tolls. You don't get paid any extra. I have noticed this on airport trips, especially to Fort Lauderdale Airport. The way Uber routes you after you start the trip tends to be 4 miles longer, several tool booths more. Yes it is quicker, however you don't get paid any extra.
I now ask for a fair review on these trips and sometimes get increased pay and sometimes I don't.
2. I have yet to get a ride request in the 40 minutes before the reservation time until I get the head to pick-up notice.
3. If you drive multiple vehicles for Uber you must be logged into the same vehicle you were logged into when you accepted the reservation. Uber won't warn you, they will leave the reservation in your list up until the 40 minutes before mark, then it is gone. In my opinion this is stupid. If I have a vehicle that qualifies for Uber X only and a vehicle that qualifies for Uber XL and I accept an advanced reservation for an X ride while using my XL I should be able to take that X reservation in my X vehicle.
4. Most reservation rides don't tip