Rear Speaker Opinions

[larryshomework]

I'm getting ready to do a stereo upgrade on my 02 (M490).

For those of you that upgraded the door and dash, do you consider rears essential, nice to have or only a mild improvement.

I would imagine that imaging improves if the door speakers are "freed" up from the stock amp. Considering components with drivers in doors and tweeters (if 2 way) or tweeters and midrange (if 3 way) in the dash.