first of all, i say congrats on your first mame cabinet.
i think you made a few design choices that i wouldn't have made, but ultimately it is your cabinet. And, if you ask anyone here, they will tell you that your cabinet is not done. It is up, working and playable, but just like everyone else, you will find things that you would like to change, and you will have learned from the previous build on how to do things better in the future. you have a working mame cabinet, which is cool, and no doubt will impress your friends.
personally, i would have taken a little more time on the aesthetics of the cabinet. it is amazing how much of a differnce a little sanding and detail work can make a big difference in the way your cabinet looks. don't let everyone's harsh comments discourage you...not everyone has the woodworking skills and proper tools to pull off some of the amazing looking cabinets that show up on this site. next time, i'd try to eliminate some of the wasted space and perhaps downsize the control panel, as well as spend a little more time making smooth seems. perhaps look into some actual tmolding that you wouldnt have to nail on. i avoided it on my cabinet for a while, and i wish i wouldnt have, it really made a difference.
enjoy your cabinet