Actually was in the Apple store earlier today agonizing over this exact same thing as haven't pulled the trigger yet on new laptop.
Being an IT professional (have ran fusion for years now for windows vms I need )I was sold on cMbp as there are plenty of times I HAVE to have ethernet and optical and often at same time with another external drive running some specific VM I use , and having all those connectors/dongles etc be required at once is not something I wanted to do.
But I'll admit I loved the look of the retina screen enough to consider dealing with it.
I lined up a non and retina model side by side and mucked around with various things for almost 30 mins trying them out. I had almost talked myself into the retina , but I can say 100% I noticed scrolling on multiple websites to "hitch" at times on the retina while they scrolled perfectly smooth on the non , and a couple of the UI menus "jerked" open on the retina while smooth on the classic.
Now the scrolling wasn't "slow" on the retina , it went down the long page fast but definitely stutter stepped it way down , while flicking the scroll bar on the classic made it glide. Doing it side by side I cant believe even the biggest retina fan could say they cant tell the difference.
So I walked out getting neither , still deciding , as again , I loved the screen's brightness and look overall , but now have to decide again between the missing port issues (not sure if want to be dongle man

) , and the definite graphical (albeit minor) issues , vs the classic.
But to answer your question OP , I dont think theres any way youd be disappointed in a classic.