Back around '98 I was buying new-in-box pins left & right. It's hard to believe, but distributors were desperate to move stock. I bought 2 MM's (not at the same time) and I want to say the price was well under 3k-mid-2k IIRC.
Either way, when I opened them up to set them up for play, I tweaked a few things and they were ready. When I picked up my MMR last year, the feeling was the same, I can assure you. Opened box, made sure everything was OK and ready for play. Talk about Deja Vu!
As far as play goes-there is NO difference! None. It is a new out of the box pin, it's going to play like a new out of the box pin. Truth be told, I like MMr better since it has enhancements that the original does not have. I also like the fact that the electronics are new, not rebuilt 20 y/o antiquated technology.