My SnapOn box has the Harbor Freight breaker bar; actually it has both the 3/8" and 1/2". I've rode them quite hard for their intended purpose and even put a 3' cheater bar on my 1/2" drive one. Neither of the tools are showing any signs of deformation on the heads or yokes from the past few years of use. The chrome on them is kind of thin and wears on the hard edges much more than some of my higher quality tools but for $10-15 each I'm ok with a little chrome wear. They break stuck bolts quite well and allowed me to spend more money on tools that benefit from more precise machining and better materials.
I'm not brand loyal and tend to buy what I think will work the best and that's priced fairly. My box has a mix of tools from Harbor Freight thru SnapOn in terms of quality and pricepoints. The vast majority of my tools are mid grade stuff but for stuff like a breaker bar that is such a mind-numbingly simple tool that doesn't require an ultra precise fit (just going into a socket drive end), I see no reason to spend the extra coin on a brand name tool for this use. It's just a metal stick with a common drive end.
Here is a video I found comparing a few brands:
Just looking at his video, all four seem to have about the same temporary deflection under load. All four popped back straight (my HF bars have had repeated use and aren't crooked). All four generated about the same amount of torque.
