Arcam AVR-300 vs. B & K AVR 507 vs. Rotel RSX-1067

AVR507 is much better IMO than the other 2. Very powerful, non-current limiting amps, and great build quality. The pre sections of all 3 are very good, it's the amps that make the difference - especially when driving low efficiency speakers.

Those speakers are power hungry, get seperates, plus seperates will sound better than any reciever. I almost bought that same Rotel, I bought a Rotel processor new, and used amps from AGON and never looked back. You have too good of a speaker for an all in one box reciever.

i have used a b&k 307 receiver with aerial 10t main speakers for a while. i believe my sound improved when i put a sherbourn amp in the system. the 10 t's just like a lot of power and it is well known they sound better the more you give them. it led to better bass control and a bit more neutral sound, the b&k leaned towards warmth. i think your speakers have the same characteristics. i am now looking for a seperate processor and a seperate 2 channel preamp to complete my system. i did not audition the other units you are considering, but i would also look for seperates and as many clean watts per channel as you can get.