MM is WAY easier than through-the-floor connectors. I can say this empirically because I've had MM connectors, and I did through-the-floor on my notch.
Unless you're making huge power and want a ridiculously rigid structure, the MM setup is more than adequate.
Paul.
How much stiffer would you say it made the chassis? I'd like to know because I would like to have more rigidity, but not ready for a full cage just yet. What do you think, worth it?