I received the MB8000 system last week and hooked it up to an Onkyo TX-SR508. And it is pretty good.
The only downfall for my setup might be the cheap philips DVD player that i use for CD's and 12guage Cables from Monoprice. I ordered a Yamaha DVD/SACD player which comes next week.
You are most likely not going to have an epiphany but but there will be chills down your spine hehe. For $300 these speakers are a monster deal! (i paid $350 like 2 weeks ago lol, i might price match if i dont return them)
I am still playing with my settings on the receiver but I ran Audissey like 3 times so far and moved my system around (my room is almost empty right now lol 15x16x8.5). At first I thought the sub is just being ****** and muddy but Audissey did a really good job on the second run but the sub was still being muddy and overbearing.... so it was really annoying. I moved my setup against the wall instead of against the window and hooked up the rear speakers too. Ran Audissey again BUT this time i had my sub Volume at 1/4 not at 1/2 which was last time and Audissey gave me a +5db on the Sub and it sounds SIGINIFICANNTLY different. Now I have it at +2db.
The sound is clear and powerfull but not as clear as I want it to be (probably because of my crappy mp3 to cd conversrions and the ****** DVD player) The bass is good but it is still an 8" sub, but it fills my room real good and if you are upgrading form PC surround or TV speakers or other HTIB I think you will be very impressed. It does take some time to figure out how to setup the sub. I have mine sitting close to the center of the system and left speaker. My settings are 150Hz crossover (done trough the Reciever) and +2db and the volume knob on the sub is at about 1/4 from minimum (my speakers are at around -6 to -8db)
Music:I tested it with a bunch of music form my limited CD collection and I have and "Shine On You Crazy Diamond" sent chills down my spine but there seems to be a soft noise coming to all my tracks out of somewhere and I cant tell if the speakers are very clear but I am very impressed.
Movie: I only watched one movie, Watchmen Collectors Edition DVD, last night and....... it was SOMETHING! The music the special effects, the rain were all there and very clear and at times i found myself turning down the volume, really impressed with the surround sound. The bass was awesome too and it did fill the room and it didn't seem underpowered or muddy but it wasn't breaking any windows either. I watched it in Dolby Digital. I think this system nails it for movies, really awesome, i cant believe i've been living without a surround system for movies.
Considering the price here is my score (so far considering the price):
Music: 7.5-8
Movies: 9
Bass: 8
Clarity: 7.5
Overall: 8.5 i think
Consider those "ratings" with my limited listening experiences experiences and the "garbage in, garbage out" factor of my CD/DVD player.
Considering all I've said all that Energy Speakers just sent Amazon 1000 units (according to the Amazon rep) of Energy Take Classic 5.1 system. It is some kind of a special order/edition and I've been looking for those speakers everywhere considering the raving reviews about them. The price is $400 and I ordered them as soon as i saw them but in order to get my money back for the Pinnacles MB8000 i have to send them back next week

........ it looks like i have a verry small window where I MIGHT be able to compare the two systems side by side.
Consider this....... I almost bought a very good condition used Energy Take Classic 5.1 set on ebay USED for $350 and a mint set for $500..... both sets went quick..... and you cant find them everywhere else now sice they got "discontinued"..... I really hope the reviews are right about them and I don't send my pinnacles back for no reason.
I really hope I get a small window to put both sets side by side and decide.
The MB8000 are real awesome btw.... i think they will be amazing for movies....