While I agree with JVC that there is a difference between 5.1 and 6.1/7.1; the difference, to my wallet anyway, would not be worth $1000. I can tell you that going from a Technics to a a Yamaha will make a sizable sound improvement.
I recently upgraded from a low/mid-end Sony to a Yamaha 1500. The difference was amazing.
One word of warning, if you think your speaker suck that reciever, and I'm assuming it's the 2500, may painfully prove you right.
Depending on your budget, you may wish to consider holding some cash back for that realization. The most talked about difference between the 1500 and the 2500 is the extra component video input present on the 2500. If that is a consideration then the 2500 is the way to go.
SAB, I'm not trying to disuade you from the buying the 2500. Honestly some of the advantages of it have me wondering "what if?". But at this point I really have no complaints about my 1500.