In addition to the Festool track saw, I've used both the OF1400 router and my Festool jig saw with the tracks. That can very much be a problem solver sometimes as well as an effective way to do certain things very accurately, particularly with the router. Track guided tools are really a step above running something along the edge of a board or something for sure. BTW, Makita tracks work with the Festool tools and vice versa. None of my stuff is cordless, just to be up front. If you do want to go cordless, pick the system that supports the kinds of tools you want to use with it.
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The most expensive tool is the one you buy "cheaply" and often...