Forget the 2006 used...new 2007...

[coolmazda5]

Chrysler Pacifica
MB R-class
Taurus X
(If you option them correctly)

...(scratch) but those are not under the same Mazda5 "class" (if "class" exists for this car ).

IMO those are more of a full-size "wagon"-ish cars, if you know what I mean. If the Mazda5 was be based on the Mazda6 rather than the Mazda3, then I think it would make a little bit more sense to compare to those above (dunno)

 

[slvrsleeper]

Mostly the changes deal with minor ergonomic gripes. The rear seats all have two arm-rests in the 08, the rear AC vent and fan speed controller ( good in the summer with little ones. The auto climate control is now standard ( on the 07 it was an option on some trim levels) The center stack got a minor makeover and the obvious cosmetic changes to the front and rear fascia. Like Jandree sez, the biggest change is the 5 speed auto which will net you a minor MPG improvement. Personally I don't care for the new nose or the LED taillights so I would go for the 07. Maybe you can waffle a little and get them down to 17,500 on the 07?