Really depends on how loud you listen to your system and your preferance.  I had a seven and at higher dbs it is by far superior to a classic stereo set up with sub but then I really only rarely listened to it with the volume high enough to tell the difference.  I now use two two ways and a powered sub and am content with saving the space and effort. High wattage units tend to sound less as good at low volume levels.  A rule of thumb I used was half volume on the receiver is optimum sound. Matching is critical since if your speakers put out 60db at 1 watt and your receiver is 100 watt to get optimal you will be kicking out over 90db. In layman terms, the walls will shake and the cops will be knocking on your door.

I'm actually more of a stereophile than a audiophile. Although the system in my bedroom rocks, flat screen, Jvc DVD, modular stereo with sub.  My audio main stereo is pre-tarriff Kenwood modular dual power supply 0.008 thd @ 1 watt and 1,000 hz. Clean!!!!!!!! Over the years and literally thousands of dollars and payments, I've learned one thing. There are only three parameters for speakers.  Power to volume (watts/db), high and low range (frequency reponse hz) and most important and the only thing that counts, your ear.   The sad part is you won't know how it sounds till you get it home for the surroundings establish the sound, one of the things Bose realized early and made their company. Size means nothing since you can get the same dbs out of a cube as a tower where stategic location means everything.  Best setup I had ever had speakers suspened from the ceiling with sub in a corner. Damn, it rocked but so did my neighbors.

Best you can do is try to get an idea what you want, cross the specs, and buy the best after a comparrison hearing at the store and be happy.

Ditto the plasma.  Cost way too high but damn I want one!!!!!!!!!!!!!!