ATI 2007 or ATI 1807


I am contemplating on one of the above. I have a small listening HT room
10ft x 10ft and I am presently using a Yamaha AVR RXA-3010 in a 9.2 set up.
I am planning to hold on to the Yamaha for now and use it as a pre-amp and buy a ATI 1807 or a 2007 for better dynamics and so on..
It their a huge improvement in sound quality with the ATI 2007 to justify the extra cost over the 1807?
I would be most grateful for any advice please.
morganmadden
Post removed 
Ok all, thank you for all the advice. I have now purchased the ATI 2007. I am thrilled with it, but really only since I ditched the Yamaha RX-A3010 as a pre-amp and substituted it for the new Yamaha CX-A5000. What a pairing!. I can hear every nuance, such doors closing, sounds in the back-round I did not take notice of before and so on.
The Yamaha CX-A5000 is a huge leap up from the RX-A3010. There are several rave reviews for the 3010 and it is a good receiver, but the CX-A5000 IMHO is streets ahead and everything all the current reviews are saying- great value for $ and probably under priced. Paired with the ATI 2007...
Audio nirvana at last!
Congratulations! I really think ATI should be better known. Excellent amps. Also heard good things about the Yamaha. Enjoy :)