The fronts are JBL HLS 610 rated at 88 dbl sensitivity. I'm sitting about 10 feet from them. The rears I have are even less sensitive.
Last night the neighbour underneath my flat was out so I tried 0 dbl on the AVR 135. Really loud obviously but not that distorted ugly loud. Really impressive actually.
All this will change when my Axiom M60's arrive - rated in room at something like 93 dbl.
The AVR 240 has an extra 10 watts per channel but it is also rated at +-35 amps rather than the AVR's +-25. Not sure if that makes a big difference or not.
I was actually hoping to get the AVR 240 but up in Canada H/K costs a fortune. I have no complaints with the 135.
Cheers,
Jordan