A significant personal upheaval recently took me to Las Vegas for a week, and while there I rented a minivan from Hertz. The first car they provided us with was a 2006 Toyota Previa:
Based on my experience owing a Toyota Matrix, I expected this car to be easy to operate, stone-reliable, and to have really uncomfortable seats. Well, I was right about the seats. Awful, cramped, squishy with absolutely no lower back support. But after driving for 15 minutes (temperatures in the low 80s F), the AC would stop working and the engine temperature would peg to the redline.
I took the car back to Hertz and they replaced it with a Pontiac Montana SV6 minivan:
This car was great! The driver's seat had enough travel and adjustment that I could get my 6'9" self comfortable, and the seat was supportive. The controls were simple to understand and clearly laid out. The on-board computer was especially nice. A set of three menu buttons atop the center stack, with a red alphanumeric display embedded in the speedometer. The driving dynamics were reasonable. Plenty of body roll made for slow transitions, and the tires had abysmal grip. Somewhat underpowered, with a lazy 4-speed automatic made for easy cruising. The AC worked perfectly on a trip through the mountains outside of Vegas to Hoover Dam.
All in all, I have to say I much preferred the Pontiac to the Toyota. If I were in the market for a minivan (which I might be, since the personal upheaval was my wife and I adopting a new baby), I'd be tempted by the Pontiac (or it's Chevy clone, the Uplander).