Oh so subtle Tim
Well, it was in jest.
The thing is, I have no idea what matty shoots and in what sort of conditons. I do know that having a camera with a high pixel density means that there is the temptation to rip the files apart by peeping them at 100%, and making comparisons between cameras at that level needs to be conducted with some caution. But if it's the actual images that are a disappointment, rather than the pixels then that is a whole different matter.
The thing is, across the internet I've seen no evidence to suggest that the 7D is inherently a poor performer - the very opposite in fact. Maybe it comes down to a different approach to PP to get the best performance from it.
The point is that in order to fix the problem you need to know where the problem exists. Is it with the camera, the lens(es) the PP or the photographer. I suspect the only person able to fill in the answers is matty. Certainly I think that switching to Nikon is a pretty dramatic step. And by that I don't mean to slight Nikon in any way. I'm sure their stuff is every bit is capable, maybe more so in some cases, but if the problem is not with the camera it makes little sense to change it. The original problem will still be there.
It's like changing your whole car because the wet weather handling is poor, when all it really needs is a new set of tyres, or better skills in wet weather driving. I suppose if you changed the whole vehicle you'd get the new tyres as well, thinking that the new car was the solution, when actually it was just the tyres. That's an expensive fix to a minor problem.
You know, when you start to examine people's raw files you can often discover a lot about the quality of the photography that can easily be masked by PP and resizing for the web. I recently took a proper look at a raw file that was pretty poor. The PP to try to fix it did nothing to help. It just looked shocking. Once the problem was identified as a filter wrecking the IQ, and was removed, subsequent raw files came alive and the PP was able to be subtle and the end result was actually very good indeed. Replacing the camera was absolutely not the answer, but I think the camera was getting the blame for the problems. Be sure to fix the problem, not the symptom.
By the way, I'm a slow runner because I'm an overweight lump closing in on fifty years of age. I doubt very much that changing my shoes would be the solution. Shedding 5 stone might.
