4 Hour round trip (which is about $40 in gas for me), plus small amount of wear and tear on my vehicle, and 4 1/2+ hours of my time is definitely worth something to me. At LEAST $200, probably more if I sit down and calculate.
So $300 for the cheapest Makita 118 track.
Festool lists the 2700 (106 inches) at 465.
The 3000 (118 inches) is 545.
If all you want is to run your Makita (or Festool) track saw, sure, go Makita. I wouldn't have an issue. Not sure how long the groove thing would take to come into play, if ever. It could become a problem down the road, and cause some regrets. Dunno.
What if you have other Festool tools you want to run on your track. Now the Makita track could be a problem.
What if you want the Festool track with holes in it? Or the track with stickies to attach when you can't use clamps?
Someone mentioned mix and matching being a problem, and I would agree with that. So you're going to have a separate set of tracks to run this stuff? Now it becomes a hassle and extra storage.
If you don't want to buy/deal with the 3000, just pick up 2 or 3 1400s. They're not that hard to line up and are more flexible than 1 big.
Time is money, even if you're just a hobbiest. Unless you're single with no kids and nothing else to do $300 may (and can) be a lot short term, but it's not that much long term vs making things streamlined and simple.
Sometimes it's cheaper to spend the extra money.