Yeah Will - I specifically don't want speaker breakup, as the drive really comes from the preamp. I'm not into blues, and I don't use a crunchy sound - it's balls to the wall distortion, and I need it precise and defined.
I also play very loud, and the bass that comes through in my drop-A tuning tends to make the sheffields get a little farty in the low end (only at very high volumes, kinda 5+ POST on the 5150-II!). These speakers should take all that abuse and beg for more :)
Roo
HTH, thanks for the info - I've been looking at the G12K-100s, might well do that as they don't break the bank like these suckers do!