So as I see it the cMBP is stable/proven, screen is snappier, its upgradable so you can get in cheap for now (relatively speaking) and you get additional ports!
No negative comment so far, all you lack is a few extra ounces, a bit slimmer and the Retina bugs which Some have reported.
But with the cMBP you can update the SSD and Ram later with no I'll effect.
Bottom line cMBP would be the wise way to go, many reports say they don't notice the retina unless they get real close. is this a correct summary?
I think the cMBP 2012 is good to go IF you don't try to compare it with Retina.
I had a 2011 cMBP and I moved on to 2012 rMBP...
Differences are actually a lot more pronounced than stated:
1) At 1680 x 1050 screen resolution, yeah, there is virtually no difference between screens from what I can see... but at 1440 x 900? You'll see the difference between Retina and cMBP plain as day. Retina can display an effective 1920 x 1200 desktop so the difference in real estate and size is even more noticeable at that setting. Also Retina has wider viewing angle, too. No comment on contrast/colors since Retina "cheats" with a wider viewing angle.
2) Retina is noticeably thinner. Even if it's just by 1/3 thinner, Retina feels like it's literally half the thickness and weight of the cMBP I had. It's even lighter than my MBP 13".
3) Retina has a perceivably smaller bezel around the screen.
4) Retina's profile is less rounded and a bit more squarish.
But you are right on the following:
1) Retina feels buggier. The graphics drivers under Mac OS X still needs a few updates before the interface is comparably smooth to cMBP. cMBP is a lot smoother than Retina still.
2) Retina lacks a dedicated mic input port (quite a big deal if you ask me) and no Firewire or Ethernet. Some legacy network devices still require an Ethernet connection for configuration, so the omission is at a bad time.
3) MagSafe 2 is incompatible with older models, and it's an annoyance because it yanks off easier than the last 2 models (being that it's thinner) and the connection overall is just... not strong.
So there are still benefits to cMBP, but honestly, don't compare cMBP to Retina. You'll feel bad for many reasons other than the screen.