Been playing organs and keyboards for 28 years or so and I've never once had to use a GM/SMF for any song I've wanted to play.
Obviously the arranger styles are pre recorded notes etc but you lot know what I mean - Keep it 100% live as possible, that's my motto.
I do actually do backing tracks for singers on the pro UK club circuit and some who do the ships and army bases using things like Pro tools, Cubase.... but that's a hobby of mine when I've not got my head buried in a synth or T2.
I always tweak any keyboard I have rather than use the internal styles and sound set. I think it's a must for anyone to learn how to use what they've purchased if they've got the time and know how, editing sounds and styles opens up a whole new ball game and you reap the rewards at the end of all your hard work put in.
Enjoy your music, you only live once