You lose the "cab feel", but I like the podium-style 4P cabs. You can just stand it in front of your existing TV and start playing, and you don't have the problem of the cab having to be really deep to allow the side players to see the TV at a decent angle. (like on Night's cab - those side players will have a hard time seeing the screen sometimes.)
You can shave a lot of width off by reducing the number of buttons on the side players too. Putting a trackball in the middle adds a lot of width, so you might have a trackball + classics cab in one room and a 4-player + fighters cab in another.
If you like beatmania-style games, think about arranging the buttons so that you can access them like a music keyboard. You'll get used to the arrangement for fighters no problem, but if you arrange for the classic fighter layout you'll be in pain if you play beatmania.
Here's my podium-style cab:
http://www.bkgrafix.net/arcade.htmIn the picture it's standing in a corner in front of the TV I just bought a while ago. I'm about to move, so eventually it will be a part of my living room.
I kinda forgot to measure right, so there isn't room for a computer to fit inside (base is too narrow and not quite deep enough, can't fit both the coin mechs and the computer case.) The buttons also aren't arranged very well for beatmania, which I'm regretting... and building a second panel because of. I think I should have avoided putting a trackball into an angled panel, because the trackball veers to the left when it's spun up, and veers up when it's spun to the left. Other people seem to have that trouble too, but on my panel it's pretty severe. The angle is too steep anyway though - it's somewhere around 15 degrees. I should have made it closer to 7 degrees.
Happy cab planning!