It would also go some way to redress the only real criticism of the current 7D, namely; not great low-light performance.
Are you aware of a better-performing cropper in low light?
There isn't one - certainly not the D7000/Pentax K-5.
Bigger pixels
do not make for better low light performance - this is uninformed internet hogwash for which there isn't a single Real World example that I'm aware of (although there are innumerable examples that
disprove the notion) - and
my 7D will happily produce fantastic low light/high ISO images all day long.
If you want better low light performance, a bigger sensor
might give you it (despite the fact that the 7D easily kicks the arse of most of Canon and Nikon's older FF cameras, so
that's no cut-and-dried), but an APS-H sensor with 18 mps won't make any significant difference whatsoever to noise performance.
Indeed, the 7D is
massively better than the APS-H 1D MkIIn that I used for a while a few years back - that only had 8 mps, and comparatively
huge pixels.
Converting and processing your files effectively
will improve low light results though.
Read
this and
this from
Roger Clark (someone who has forgotten more than most people here will ever know about matters of sensor technology and performance) about the capabilities of the 7D's pixels compared to those of the 1D Mk IV.
He knows what he's talking about, and he tells us quite unequivocally (owning and having studied and tested the pants off each camera) that
in fact the 7D's sensor - and therefore its pixels - are
more "noise efficient" than those of the 1D Mk IV.
Bigger is better? Not where pixels are concerned.