The one side burned up super fast and the other didn't light right. Very odd. And the amount of ash is surprising. I was giving it a fair shake, I want it to be good. But for whatever reason it's not working out for me. Maybe for grilling but for a long cook might not be ideal.
I could be wrong, but it sounds more likely that one side didn't get enough lighter fluid or something else happened. Otherwise why would only one side of the basket not light properly?
No matter what brand of charcoal, if one side didn't light properly (for whatever reason) then I would expect that side to burn up quicker, and I would expect the overall temp would be lower and would slowly climb as the unlit side slowly lit. It just makes sense (at least in my head - which isn't saying much).
I'd give these another try before ruling them out as a bad brand.
As far as the ash level, if you are comparing almost any brand to stubbs, I can imagine the ash level must seem very high. Stubbs is a premium briquette with no fillers, and therefore very low ash. Kingsford Competition will also be lower ash, but I don't know how they compare in price to Stubbs.
One more note on the particular briquettes you got. I have noticed the 50% larger ones seem to take a little longer to get going full on. There is less surface area per lb of charcoal than regular sized briquettes. THAT right there may make them unsuitable for the PBC with it's controlled air intake.
If you wanted to try a regular sized Royal Oak briquette, grab a small bag of the GrillMark brand from Ace Hardware. But I guarantee you will still have more ash than stubbs.
The bottom line is use what you think works best. If you like Stubbs, you may want to stick with them.