[Gandalf1953]

I have been using DSLRs for approx 6 years starting at entry level then mid range and I now have top of the range but not full frame.
This last camera was a replacement for one that was stolen.
It is dogged with dirt on the sensor problems. I recently had to return it to the manufacturer for repair and clean but find it has still come back with a dirty sensor.
My previous DSLRs never had such a problem and it is driving me mad.
I am therefore contemplating selling the whole lot and starting again but the question is, what do I go for?

The choice seems to be Canon EOS 70D and Nikon D7200. I use 18-200 mm lens which is ideal for my needs and I have a 50mm lens.

Which one would you go for and why?

I'm with Bob in that it depends on the breed of glass you have, if you are happy with your existing lenses go for the camera that can utilise them. At this level all the Canon/Nikon bodies are excellent cameras that will not disappoint, some people have a preference one way and others will choose the other but there is no right or wrong. Ask yourself what type of photography will I be doing-landscape, wildlife, sports or video, answer this then go for the camera most suitable for your needs. Also consider buying 2nd hand there are many good cameras on the market just a couple of years old and lightly used where your £/$ will go much further than buying new.
Regards John