Feature:
I only give a 9 because I'd like some Speakons with the 1/4". Otherwise everything necessary is incorporated. I am also not a big proponent of built in crossovers or filters on amps and so the lack of this doesn't bother me. I use external crossovers (of my choice and settings) anyway.

Quality:
I've had my Servos over ten years without a hitch and frequently pushed. I've used Carvin (great), Peavey (good), Yamaha (good), BiAmp (great), QSC (great), Behringer (marginal), Crown (crap) and Samson is by far the best quality for the money.

Value:
If you just want watts for your dollar buy a Behringer and settle for less than perfection. When you tire of the not so stellar and lacking the advertised performance, then buy a Samson. Again, all things considered, Samson has been the absolute best quality for the money.

Desirability:
What's not to like...the soft blue illumination as this thing lurks in your power rack waiting to unleash the best your system will be.

Sound:
I own three Servo amps...one (550) drives my high/mids for the PA, one (500) for the subs on my home theatre, and one (260) for my guitar rig. The sound of these amps is pristine even at extreme dB levels. No distortion, no coloration, no extra noise. Oh and no fan cranking in the backround and this amp runs cool with natural convection. Excellent for a studio amp also.

Ease of Use:
Standard in/out, crank the controls and enjoy.

Support:
Never had to use them but again that speaks of the quality.

Overall:
Samson makes kickass power amps and you will not be disappointed once you hook up.