I'd be curious to know what prompted this query. Maybe because you've been Live-ing in an alternate universe for too long and now finding normal gravity to be disorienting?
I'd much rather save a track template than a synth rack, for the simple reason that it means far less effort. Your next step is
always going to be to route those synths somewhere, and the track template handles that for you. Not to mention automation (e.g. CC11 on every orchestral MIDI track, CC7 on every audio track) plus bus sends. Nowadays, I can simplify it all even more by including an aux track in the template so that my reverb (or whatever) automagically appears in there, too.
Plus, I can't think of any two projects I've ever done that used exactly the same instruments.