I too prefer the baby backs, even though the so-called "pros" and competition BBQers lean toward the St Louis spares. I've done both so many times, and keep an open mind, yet I still prefer the baby backs hands-down! Sounds like you ended up at 4 hours 45 minutes at 235. Seems a little long to me at 235, but you never know with baby backs, they can vary in size and quality. I'm a 225 person for ribs and brisket. Sometimes I think the higher temps come from traditional BBQ methods, where it is more challenging to keep the temp at 225. When I used to smoke on my WSM, 225 was a bit of a challenge to maintain for extended cook times, but 235-250 was a breeze. I figure if I can finally maintain my ideal of 225 on the SI, I'm going to do it!