I played in a long-term campaign of DCC. It went on for over a year and it was a whole lot of fun! It really only ended because the GM wanted to step down for a while and let someone else run games.
We did start with a Funnel (which I love) but from there the GM strung together a whole slew of DCC and non-DCC modules, as well as some stuff of his own creation. Usually these were presented as existing locations where there was some item/person/information we needed to locate. He did a great job of tying it all together... yet it never felt linear/railroady. Like any investigative adventure we hit snags, went after red-herrings, and occasionally bit off more than we could kill.
My PC (a wizard) was eventually one of the highest level characters (5th level). She was getting pretty damn powerful and truncated several encounters on her first turn. When we visited (I think) White Plume Mountain she ended the mission halfway through with a single spell (which was also nearly caused a TPK, because DCC magic is fun that way).
I was thinking she might be getting TOO powerful and was planning to retire her somehow... but then she was taken out by a dragon (DCC dragons are crazy dangerous to be on the wrong side of!). It was great!
It's definitely a game that avoids 'plot armor' and can lead to sudden death, but because of that it felt all that much more satisfying to make it through and succeed at stuff.
Short term play can be great, but there are loads of stuff in DCC that doesn't really come into the spotlight until you've been playing for a while, such as relationships with Patrons (I think any class can find one) and all the possibilities contained in the mantra 'Quest For It'.