I also have the E80s with the EC35 center setup. Sounds great! I looked at the E90s also but realizing that with a crossover to the sub at 80Hz, the difference between the E80s and the E90s are minimal. Then it all depends on your subwoofer(s) which IMHO will always sound better and have more presence and bottom end than any big woofer mains. If you're not using a subwoofer, then I would get the E90s, or even the E100s, for sure. But with a good subwoofer, having the E80s or E90s set to small and rerouting the crossover to the sub, there really isn't going to be much of a discernable sound difference, especially given the price difference. FYI, also in my setup I'm using four E30s along the back for 7.1.
I have the E250p JBL sub, which does sound superb. I first had the E150p and it just didn't measure up. It literally sounded "small" and thin and I had to crank it to get any resonance and presence, and by then it's internal volume was at 3-4 o'clock so it was making a "cracking noise" with the hard pulses of the LFE. I'm sure the E150p would be fine in a dorm room or very small bedroom, but my room is 15'x22'x10'. So I exchanged it for the E250p and it was not just a noticeable difference, it was a tremendously obvious difference. However, I'm sure it's not the best of the crop. I, like everyone else around here, aspire for an SVS PB12 sometime in my not-to-distant future.
Anyway, my point with this subwoofer pontification? With a smaller sub, I suppose the E90s or E100s would be necessary, but with a good 12" (or bigger sub--do they exist?) sub, properly calibrated, the need for the E90s/E100 bigger woofers isn't necessary. Go with the E80s! And take the difference in cost from the E90s and put it into the subwoofer.
