It really depends on what is important to you. For me, having an accurate CP layout is the most important, so I went with modular. I didn't want 40 or more full CPs, so swappable didn't make too much sense for me.
I also don't swap panels all that often, but I don't actually use it all that often either. All of the dedicated games out in the garage usually take up my available time. It is nice to be able to play what I want with the actual controls when I have the time now.
I also don't see fast swapping as being all that important (although I can usually swap out the panels in less than a minute). When I first started playing on the cab, I thought it was great to flip through the games, but that wears off. I was rarely even finishing a game because I was always racing to see what is next.
I have had my Robotron setup on there for a couple of weeks now, and I like the fact that I am going to either play Robotron, or have to swap. I will usually play the game more, but if there is something else that I really want to play, then it is worth the effort to swap. Again, the effort is minimal. Being able to have 2 4" Wicos and two start buttons, and nothing else on the panel, is a great thing.
I think the people who expect instant gratification in MAME have not had a bunch of real games to mess with; there is always something that needs to be worked on!
