I'm doing this backwards, as I got burned out on Breaking Bad after marathon DVD viewings and gave up about midway through S2. I still plan on going back on watching the entire series, as more than a few people have told me that S3 is when things really hit their stride... So I'm blissfully ignorant of any significant BB characters waltzing through the Saul shows.
Just finished off the last three eps on the DVR and I really liked the first season... even if I thought it started off strong and then limped a bit to the finish line, but looking forward to the next season where it appears obvious that his Slippin Jimmy con act is going to heavily influence his lawyerin'... and the retired cop / parking attendant / criminal for hire guy always had interesting subplots when he was used... I can only assume he is one of the BB characters of which I am blissfully unaware.