5 stars from our party of 3! Stopped here after missing all the more notorious Austin/Waco locations, most of which were closed on a Sunday or too early on our drive for us to be hungry. We stopped at the notorious Czech Stop an refrained from chowing down on our kolaches to drive 5 miles further north to hit Up In Smoke.
It was delicious! My friends and I all got the combo (2-3 meats of your choice - $10.95) and got brisket, turkey, and sausage. The brisket was fresh and juicy (even at 8pm, an hour before closing). The turkey was smokey without being overly flavored/seasoned. The sausage wasn't greasy and had great flavor. We all agreed that the spicy BBQ sauce was a new favorite (and one member of our party ate 2 servings of spicy sauce, despite not typically liking sauce). It isn't super spicy, but has a nice kick.
There were a plethora of sides (new potatoes, mustard potato salad, pea salad, fried zucchini, baked and pinto beans, etc) that were all serve yourself (as much or little as you like). Potato salad was fresh made and tasty! Baked beans were amazing. Zucchini was crispy and flavorful. The new potatoes could have used more seasoning.
Service was good and friendly. Atmosphere is about what you'd expect for roadside BBQ, but the place was clean, well stocked, and the bathrooms were clean, albeit outdated. It was nice and chilly due to the kickin AC even on a 100+ degree Texas day. You can buy meats/sides/sauce in bulk and it appears the facility caters.
If you are an experienced BBQ enthusiast  with super high expectations and a palate for only the best of the best, this might not meet your standards. For the other 97% of you, I highly recommend this one of a kind BBQ stop! Thank you Up In Smoke!