351m or Kac 929

I was wondering which amp to buy, although i  am not a big  fan of kenwood my friend bought a Kac 929 its rated at 1000 watts which i know it  comes nowhere near that but its around  $279 canadian before taxes.

Also my other friend bought a 351M Rockford amp but i can't really tell how good it is because he has 6 subs and clarion and this amp. when he hooked it up it didn't seem to make much of a difference.  The 351M is rated at 377-385 RMS and i was just wondering which would be an overall better amp. I can get this amp at $ 260 before taxes, its originaly $317.  

The kenwood being a 2 channel as the rockford is mono.

I would definitely go with the Rockford amp. Much better then the Kenwood.

Okay, in Physical size the kenwood is much larger then the rockford.  Does that make a difference or no.    

I also heard rockford overrates their power series amps is that true ?