I bought (and still have) an original AFM from back when the game was released.
FWIW - and not to throw gas on the dimple-gate debate, my original WMS playfield has plenty of dimples in it. And I don't care. I never even noticed them until Pinside made a thing of it several years ago.
As for Remake vs Original, I played AFMRLE at Showdown a few years ago and was blinded by it. My daughter had the same reaction. Both of us really disliked it. I am not anti-LED by any means - but the LEDs in AFMRLE were simply too much. They were SO bright. I don't know if there is a brightness adjustment on the CGC games but I'll take my incandescent bulbs all day long.
As for gameplay, I don't remember any noticeable differences. The remake pretty much played like the original but I may have been so blinded by the LEDs that I may not have been paying that much attention to the game play.
Putting a ColorDMD on the original is a solid mod. I'm not a big mod-monster but ColorDMDs are definitely one thing I do upgrade on my games.
Bottom line, as others have said, is to buy which one you like best. Any purchase boils down to personal preference. It's AFM either way - so it's not so much about the game itself (IMHO) but which incarnation of it you personally like better.
Good luck. You can't go wrong either way.