Pieter, welcome to SMF! Glad you're here and asking questions right off the bat.
I'm not a huge fan of sweet, but it does have it's place.
On beef and bison, I rarely use sweet. Salt-Pepper-Onion-Garlic (SPOG) is my beef go-to in just about any form. I do have one recipe for the grill where sweet is included because it helps a particular cut of beef char better, adding to the flavor. For almost all the other beef I put on the grill or smoker, no sweet at all.
Pork? Sweet goes well with pork. I have used just SPOG quite a few times, but usually migrate back to adding sweet in some form, usually in the form of sauce and/or fruit.
Poultry? Kind of a 75-25 thing for me. I like savory 75% of the time. I like sweet and savory about 25% of the time. The sweet usually comes in the brine though, or the sauce, never the rub.
Lamb? SPOG again with occasional sweet sauces.
Smoke it the way you like it and enjoy every bite!