The Slab is in Ferndale, not Bellingham, which is not good. Anywhere near downtown, that's where Western Washington University is (and the two community colleges aren't far away). Ferndale is about 8 miles north of downtown Bellingham. Very out of reach.
Besides that...I had no clue up until Googling just now, where/what the Slab is. It's still not clear to me. Never been there, never heard anyone mention it, nothing. I know people from Ferndale who do shows and performances, and I've never heard them mention it.
Now, the show at Hot Shotz, that's a prime location, right near downtown Bellingham. You'll get people showing up there not even realizing there's a show.
I've got a feeling both shows will draw about the same amount of people. I just hope FAB/Quinn don't spread the word that Bellingham is ungrateful, or doesn't support hip-hop, because it's not true. E-40 and Blue Scholars both sold out, and FAB/Quinn would too in downtown Bellingham.