I owned a Festool TS75, the "big one" briefly. I had the 55" track and the 120" one. I realized it was an impulse purchase and I didn't need the system since previously I use a saw guide and my circular saw to break down 4 X 8 sheets. For that I needed 2 sawhorses and four 8 ft 2 X 4's to support the plywood having one on each side of the cut line.
I did purchase a 2" styrofoam sheet to put under the plywood, but never used it..... yet. You need the material at a convenient height to pass the saw along without kneeling on the ground and still reach to the center of the width while standing. I worked outside when doing this, weather permitting. My shop is up 15 steps, on the second floor, so carrying up a 3/4" sheet was no going to happen. That was the entire reason for the track saw or saw guide.
About a RAS. I wouldn't have a shop without one. Here's why.
The table saw is the best machine for ripping various width material from 1/8" thick to 30" wide. Period. It can cross cut lengths reasonably safely and accurately up to around 4 ft. Longer than that, it's unweildy because the miter gauge even with an extended fence has to push the entire weight of the plank through and past the blade.
Cross cutting heavy planks of hardwood on a RAS is a snap. You now only have to move the saw carriage, not a heavy plank. It is also fine for crosscutting workpieces down to 3" or 4" long but after that it gets too short to hand hold them safely. So, back to the table saw with an extended miter fence or a sled.
Making shelving or cabinets or a library ladder with a dado set in a RAS is a snap: https://www.woodworkingtalk.com/f27/...ing-ras-47095/
My RAS has an extended table to the left side for supporting longer planks:
A good discussion RAS VS sliding miter saw:
I made this double miter gauge setup for more control cross cutting longer and heavier planks, BUT it also works great on short stock as well. It's a sled of a sort without the bulk:
Here's a build I did on a large sled with adjustable fences for miters: