If it's the Blazer Brass line, then it's a toss up. Both brands of ammo have worked flawlessly for me in the past. If it's the aluminum cased Blazer, then I'd go with the S&B. I just have a preference for brass cases over aluminum. That's mostly as a reloader, but still.
One item of note: those I've never noticed their pistol bullets to have any steel in them, I have had a few S&B rifle bullets that had steel jackets. Not sure if it was a limited time thing or if it's down to specific lines of ammo, but I figured I'd mention it. That may or may not be an issue to you.
Also, if you're just looking for cheap practice ammo, Prvi Partizan and Magtech are also priced fairly low and are both reliable. I shoot a lot of Prvi Partizan in my handguns, and even bought 5 boxes for their .30-30 ammo for my brother a while back. That's probably enough for the forseeable future, and he's gotten every deer (and a few hogs) that he's shot with that ammo.