A FlyerTalk Posting Legend
Join Date: Jul 2002
Location: MCI
Programs: AA Gold 1MM, AS MVP, UA Silver, WN A-List, Marriott LT Titanium, HH Diamond
Posts: 52,575
On return at PHX, they drive you directly to the terminal in your rental car. No need to "connect" back to the regular shared shuttle bus.
In other words, I figure you lose about 5 to 7 minutes on pickup (thanks to the extra hop over to Silvercar), but then gain more than that (maybe 10-12 minutes) on the return, because you don't have the variability and wait for a shuttle bus back to the airport.
I'd totally do this again. The thought of losing a few Hertz points or airline miles would not deter me in the slightest.