Looking to upgrade my back surround sound speakers

Dont get crazy on this idea of voicing for rears surrounds as noted its not exactly in your face sound. The content will be ambient, add space and depth with some affects mixed in. There is no need to be anal about them, as long as they are in the general ballpark you will be just fine.
I used B&W surrounds with Innersound Eros so I speak from almost exact experience. Also at that distance its questionable as to the need at all but I would do it if thats what you want, just place them high on wall so the dont call placement attention to themselves.

If you are only concerned with ambience, minimal surround speakers are OK. But there is quite a lot of music where the surround speakers are important... properly recorded antiphonal music in particular. I had to upgrade my surround speakers when I realized this.

I figured its more about home theater since it was posted here and yes music is a different animal but even so for the 6 and 7th channels I would challenge most anyone to know the difference of a carefully chosen non matched speaker over a matched one. If budget restrains you from doing a match, dont sweat it too much is all I suggest.

Chadnliz... Agreed. Same goes for 8th, 9th, 10th...etc.

In 10 yrs we are going to be listening to 50.8 systems lol