When I got my first MFT about 6 months ago I weighed the same question. I wound up getting a complete 1080 set via Craigslist for $325, and it was in great shape, very few kerf cuts, etc.
I like it so much I bought another (via Bob) 1080 set about 2 months ago and use that one *solely* for assembly, clamping, jigs, etc. And I have a MFT800 basic being delivered tomorrow, which will be my portable, and extend the length of the 1080 enough to build a bedframe for the kids. Am I buying/investing in 'yesterdays' model. Yup.
Here's why:
- The MFT1080 is bigger, and it is heavier. As you said, it is something of a benefit *in a stationary setup*. My 1080s aren't going anywhere, unless I relocate my assembly area.
- The cost savings went directly to other tools. Helllloooo
- The super cool add ons which attach to the MFT3 profile aren't availabe in the US yet... who knows if and when they will be. Though I will lust after them, I wouldn't get any. I have a TS, bandsaw, jigsaw, and two router tables.
- Though the MFT1080 is lower, which I consider its main drawback, you have the option of raising it on blocks. Take it off the blocks if you want it lower for some task. You do not have this second option with the MFT3.
I have read that the MFT3 dog holes are more consistent. Here is what I've found: My two are very slightly different.
My purchased-used MFT has holes that are nice and tight on the Qwas dogs, which I measured at 19.85mm (all six precisely the same) on my digital calipers. But they are a tad loose on my "new" 1080. The threaded dogs I got from John ("ToolImprovements") are nice and snug in this newer MFT, and they measure at 19.90mm (all six precisely the same). They actually are a bit too tight for my first table, but that's ok because they're for assembly fences and jigs, not cutting alignment.