Unless you own a Ferrari dealership AES just makes zero sense in 2012. Instead of being locked into a puny handful of the crustiest oldest AES carts, an MVS (consolozied or not) will let you basically play anything made for the Neo Geo for 1/10 the price.
Sure, I know you don't think you want to play Metal Slug 3, Rage of Dragons, KOF 2003, etc...but you eventually will. Either that or you are an idiot because those games are fantastic. Rather than buying a dead end AES machine with so-so sticks, invest in a nice CMVS or upright. The extra investment will pay for itself quickly...possibly with the first game you buy. You can have ALL the KOFs for less than $150 on MVS, and all the Slugs for $200.
Of course its possible that you are one of those "I HAVE TO HAVE THIS EXACT MACHINE BECAUSE I SAW IT IN EGM WHEN I COULDN'T AFFORD IT!" people. If so, well, I hope you are either much wealthier than me or you like Fatal Fury 2 a LOT.
To the %99, the AES is like a PC Engine Shuttle. It looks nice, I guess, but it can't play %75 of the best software. Its a dead end.