Green -- NEX-5 & Takumar SMC 28mm f3.5. Click for larger.
I have done it. Today I picked up a used, but mint condition 1D Mark III that's out of the sub mirror repair range. One thing I noticed immediately, is how bad the 3" LCD screen compared to the NEX-5. When I first got in 2009, it wasn't so bad because I didn't have any camera that had a better screen, but it definitely looks terrible next to the NEX-5. Everything else though, I like it. Very clean and nice files; good size RAW files, and everything is so responsive. One of the things I could not get used to on the NEX-5, is how slow it is to turn out from sleep mode, and how slow it is respond to the enlarge button on review.
This minor upgrade to replace my 1D IIn, which I am already putting up for sale on Craigslist, hopefully will last at least three to five years. I simply run out of money to upgrade to anything else for the next while :)
My finger is crossed that this camera will not give me any problems, or I will be banging my head, over and over.