My understanding is that you still have heat/ac in the back seat, just that it's not the individual climate control (separate for each side as in front seats). Is that correct or do you not have any vents at all in the back seats without that package?

you have the center vents...the package adds vents on both side pillars. If you have passangers in the rear on a regular basis, this is a must especially in the summer.

technology package is a must. even the the NAV could be better, the RTTI is priceless IMO. Plus, its gonna be upgraded very soon to include better info. premium and sport packages should be standard, and CA is worth the money.

premium sound I could do without; you're better off going aftermarket anyways. rear climate is a waste.