I don't own a Domino ( yet ) but I think it's safe to say that the MFT-3 will be a purchase that can be of great value to just about any project you're likely to undertake.
The MFT-3 is definitely more than "just a bench with holes in it". I can envision lots of projects where a Domino wouldn't be of much use - it's a lot harder to come up with projects that couldn't benefit from an MFT-3. It's very versatile and once you start using it, you'll keep finding new uses for it, and you'll wonder how you've managed without one. For example: the MFT-3, two sets of clamping elements and a role of butchers paper make the best glue-up surface for cabinetry I've come across so far, but that's just one use - there are many, many more.
Since my trailer space is limited, I do leave the MFT-3 at home sometimes, when I think I won't have too many uses for it in the project at hand - it's portable, but only just.
In most cases I regret that decision, and pray for the toothfairy to bring me a nice van or a bigger trailer.
I really like the Domino, and I'm quite sure I'll get one sooner rather than later. But I'll have to watch myself closely, for there's an old adage that says "If the only tool you have is a hammer, all your problems tend to loo like nails...." and for me the Domino would bare that risk. I can envision myself thinking "OK, how will I fix/tackle/solve this with dominoes..." Not necessarily a bad thing, but something to be aware of.
Just my 2 cents.
Regards,
Job