EXPERIENCE and NEED is how I draw a different conclusion.
My children were trained properly on the use and dangers of all shop equipment including the tablesaw. I don't lose sleep worrying whether they'll act foolishly or with ignorance when I'm not looking.
The 75's xtra oomph and capacity is necessary for thicker dimensional hardwood, but the O.P. wasn't asking about that. And let's look at the #'s. The ts75 is 25% more powerful than the 55 and has a 27% deeper depth of cut. But this comes with a 35% weight penalty - or - over 3 1/2 lbs. So, if you need the depth, you need it. Not necessary for for plywood though. That xtra weight and systainer size makes a difference when you're moving jobsites constantly. Same with a 110" rail. That ain't easy or efficient to transport in some vehicles. Or to get in an elevator. 2 @ 1400mm rails in a storage bag fit easily in a lot of vehicles and can be slung over your shoulder bag while you push your CT+ systainer stack, or MW1000. That isn't going to happen with your one piece rail and MFT - it's multiple trips. If you don't consider 3.5lbs, or 35% "much" , so be be it. I'll bet you'd love a 35% discount or miss 35% of your paycheck though.
The 55 is powerful enough for any sheet goods. My guys and I have cut miles of domestic and euro plywood, veneered and laminate coated particle board, lacquered MDF, Medite, Trespa, honeycomb aluminum panels, and acrylic all up to 25mm thick. That's an inch. With the proper blade, the ts55 doesn't complain nor did it's predecessors. The blade must be suited to the material, sharp and the saw+vac need to be on a 20 amp circuit. Using a 28t blade to rip a 2x4 is going to be a disaster. Same with a Panther blade croscutting a zebrano veneer panel. That's not the saw's fault because it's under powered; it's user error. Use the wrong cutter and starve the motor of current, and yeah, it would seem under powered.
n.b. The Makita saw has 10% more power than even the larger ts75
All in a smaller/lighter/cheaper package. It's a very hard proposition to beat at breaking down sheetgoods for non-fanboys.
Joining two rails, accurately, takes about a minute and a half. That was the only option in the 90's when the longer rails weren't really available here. If you do join rails, get TSO's connectors instead of Festool's or Makita's offerings . In a stationary setting like a shop or a month long job, the one piece is far superior. If you take your show on the road constantly, separate rails have more advantages. Cost is a wash foir Festool's 2@1400 vs. 1@2700. But Makita's 118" rail for $225 (or less) is an absolute steal if you want a long one piece rail.
20mm (or 3/4") dog holes can be added to any work surface to utilize clamps, dogs, hold downs and other items. Festool didn't invent this concept, bench dogs have been around for ever. At one point square or rectangular holes were en vogue because it demonstrated you had the forethought and talent to build them into your bench. They weren't practical to add after the fact. An MFT isn't the only way to utilize this.
