Bottom line, crohn's is more serious because it can affect your entire GI tract ( mouth to anus) and also for part of this reason can be tougher to get under control, UC is limited to the colon/rectom area only, it too has the same extraintestinal manifestations, EXCEPT for fistulas, those are CD related only, obstructions/blockages are more common with CD than with UC, so CD is worse that UC in those regards...
Symptoms wise, you could have a mild crohnie compared to a severe UCer which would make the UCer somewhat worse off, symptom wise.
p.s. I'd rather have a broken arm than a broken leg, my legs carry my entire body and there are bigger bones in the legs than the arms which could make for a tougher recovery.
My bum is broken....there's a big crack down the middle of it! LOL :)