herky - here's a method i've used with very good results.
i did brush a light coating of mustard on (this is optional, but i do prefer to do it) and then i sprinkled on durkee's kansas city steak seasoning.
if you can't find this in your area, you can probably make your own; this is basically a mixture of sea or kosher salt, cracked black pepper, granulated garlic and onion, crushed red pepper and maybe a couple other things that i can't identify - very simple and very good.
anyway, i tossed these on the smoker and cooked at no more than 250 degrees. i did spritz now and then with the following mop, which seemed to bring out the meaty flavor of the beef and also help with moisture:
1 cup dr. pepper
2/3 cup low sodium soy sauce (i would like to try no-sodium,, but it is unavailable here)
1/3 cup olive oil
if you try this, be sure to blend the mop before each use to emulsify the oil into the mop.
when the beef ribs were about 15 minutes from being "done," i brushed on a finishing glaze that i made with this recipe:
1/3 cup ketchup (catsup?)
1/3 cup dark brown sugar
1/3 cup apple cider vinegar
simmer on the stovetop at medium heat until the ingredients are dissolved and well-blended, then cover and let cool until it is time to brush it on.
i also brushed a bit of this glaze on just as the ribs were coming off.
here is a picture of the result:
this was VERY good and the beef flavors seemed to come out very well.
p.s. - this should work just as well for short ribs or back ribs.....