I really do like and appreciate Mame and understand all the advantages. I even have plans to someday build a Mame cabinet, but it might be the last piece I add to my collection.
I enjoy having the board that feels more correct in a cabinet. For me Mame feels a bit like putting a Chrysler 440 in a model T; sure it's fast but it feels like a bit too much of a compromise. It's all a matter of personal taste. IMO building the machine is a big part of the hobby, and it just wouldn't be fun for me to install a PC in a cab. I just like the "older" feel, heck I even have all my games accept quarters just for the nostalgia factor. I also don't have the need to play every game ever made in one cab. I like the smaller easy selection of the best classics the Multi boards offer. Funny enough my 2 multi board cabinets are set up to boot to the game that matches their cabinets, and when most visitors are playing them they want to play the boot up game and tend to avoid the menus all together.
As far as the two boards go, I used to use the 60 in 1 but for many reasons (the biggest being presentation and "boot to" option) I prefer the AS board. I only miss a couple or three games from the 60 in 1 and don't even swapped back to it anymore. Hope that helps answer you question.