I bought 2.5 lb beef eye of round and sliced against the grain into 1/4" thick slices. I read online to put it in the freezer for an hour or so to make it easier to slice and that worked.
I did (2) different marinades. First was (1) cup low sodium soy sauce, 1/2 cup of Worcestershire sauce, maple syrup, garlic powder and ground black pepper.
The second was Soy sauce, Worcestershire sauce, A-1 steak sauce, onion powder and Sweet Baby Rays BBQ sauce. Both were very good but very different tastes.
I marinated the meat for 15 hours and I don't think that was long enough. Next time I will do at least 24 hours and make sure I flip the bags a few times to make sure all the meat coated.
4 hours on smoke boost seemed to be just right, I used Weber Grill Master pellets.