The 5200 is. Its huge but needs an 8" vent The 3500 is fairly large but I don't remember the wood length.
Looking at them right now. It is nice because the log length is the first thing you see unlike BK for whatever reason. So the F3500 is 20" logs and the F5200 is 22". That is a welcome length over the BK to be honest. Also confirming the F3500 is 6" and probably why begreen mentioned it in my other thread already.