AES, MVS, who cares, play the games and have fun however you see fit.
I owned an AES and jumped into MVS, I was able to get way more games for MVS (129) than I ever had with AES (22), granted some of these MVS games need to go to folks that play them more (Pop 'n Bounce sucks, thanks for that minty kit Ratson! lol) 'cause I certainly don't see myself playing some of these titles. I should sell, I know, it's a PITA though, I usually just buy, rarely sell.
If I were ever going to get back on an AES I would consider a few things:
1. Uni-Bios
2. Audio/Video Mod to stay up with the times.
3. Phantom Converter, might as well use them MVS carts as well.
4. Get into the cheap titles only.
When I look back at this list I just keep thinking I should just keep my 2 slot CMVS and be happy with that along with my MVS boards and cabs, why go AES...
...there's a thing about it, I dunno, it's weird. Back in the day it was surreal, it was awesome when KOF was hot and you'd come home to play some games after school and not even worry about subpar versions like the SNES Neo ports from back in the day...PSX also had a set of ports, better than SNES but still...
I filled the void of missing my AES when I got me a NGCD, it's console, it's cool and it offers a little different experience over the MVS counterpart, loading times are a bitch but for classic titles it's really not that big of a deal. Fatal Fury Special 365/24/7 it's the best ever!
Get one, go nuts, soon you'll get it off your system and sell it like most of us.