Nikon User Looking for 7D Feedback

Jim, welcome (in anticipation!) to Canon-land. Be aware that camera manufacturers are like banks (at least, banks in the UK): you are always with the worst one, or so it seems. So if you spend some time on the Canon forums you will see plenty of complaints, some of them justified, many of them reflecting user error or inexperience — or just plain stupidity or failure to read the manual. But you probably know all that, and there have been some positive signs recently that Canon respond to user needs, for example major firmware upgrades, first to the 5DII and more recently to the 7D (and yes, 2.0.3 is purely a freely downloadable firmware upgrade, there is no change to the hardware), and in anticipation to the 5DIII.

I use a 7D alongside a FF body (just upgraded from 5DII to 5DIII), and my 7D is used mainly for wildlife with a 100~400 or a 70~200/4IS possibly with an Extender 1.4× II. Whilst I had the 5DII I also used the 7D quite a bit for other purposes, because I found it to be better apart from the sensor size, but I am likely to limit the 7D to wildlife use now I have the 5DIII. The 7D is an excellent camera which I have been (and am) very happy with. For me, it replaced a 50D, giving much better AF and significantly better noise performance. I did not like the 50D at 800, but I use the 7D happily at 800 and with confidence in many situations at 1600, a very important difference with slowish long lenses.

You do not sound as if you are intching to move to FF, and you should with confidence take advantage of some of the excellent EF-S lenses. I have two, the 10~22 and the 60/2.8 macro, and if the 7D was my main body I would certainly buy a 17~55/2.8 - all these lenses are optically comparable to L-series lenses. As it is, when the 7D has an outing on its own, it borrows the 24~105 from the FF body, used alongside the 10~22, a very effective combination.