Had to reroute from Tucson into Phoenix due to a last minute flight change and found Arizona Shuttle as a viable workaround to get quickly and cheaply to Tucson.
The service itself is about what you would expect with any shuttle service (scheduled pickup time, van trip with people, etc) and is about the same cost as other comparable options in the area, but they do have a few good value adds which is why I'm giving them 4 stars instead of the average 3. For one thing, they use a tow behind trailer to haul the luggage so it keeps the van feeling less cramped. Secondly, they try to keep the ride as comfortable as possible with cold water and a good AC running at full tilt in the vans. Finally, they do try to space people out on the van trips so there is still some room on the shuttle to stretch out after that flight.
Overall the trip was a good experience and I would recommend using them if you need to go to another airport on short notice in AZ or get between major AZ cities quickly and in an affordable manner.