I've been in a few games of Dungeon Crawl Classics now as a player. I'll state outright that the GM for the game has a fair amount of work to do when running DCC....it is evident that the GM neeeds to get "in sync" with the expectations of the system or that can lead to A few problems. Both GMs I have played under have done well, for the most part, though one GM (ahem, my wife) I think learned following her first session that DCC expects you, as the GM, to be extremely ruthless and cruel, especially in the funnel adventure. The GM for the other game is a friend of mine and he excels at being a ruthless, cruel, take-no-prisoners type of GM so he tackles it quite well.
One of the games is at an actual live tabletop....DCC is designed for this medium of play. The other was on Roll20, and I think demonstrated that VTT has some limits. The game in question had more young kids (and parents who were maybe policing their kids a bit too hard), and managing a posse of zero level PCs on Roll20 got a little cumbersome at time (though Roll20 does have a really nice character sheet with multiple zero level slots that works great). It was that lack of physicality that contributed to much of the confusion, I feel.
All told, the biggest problem with the Zero Level funnel crawl I am experiencing so far is simply that I have one survivor in one game which I am frankly not that enamored with (this hapless zero level character survived because she is so horrific in most of her stats that hiding behind all the risk takers was the only way to go). When she inevitably dies after graduating to level 1 I am unsure how to proceed, as I don't recall in DCC if it provides advice to the GM on situations where the player loses a solitary level 1 character, and all other funnel survivors died. As is typical of DCC's approach I imagine it is left to the GM to decide what works for their table, I guess.
In the other game I have an opposite issue, with four survivors so far, and a possibility all four may make it to the end of the funnel. If that happens (and I suspect it might not because I am trying really hard to get some of them killed) then I guess I'll have plenty of prospective PCs for the future.
Anyway.....it's interesting to play DCC, but I realize now its not really my cup of tea as a player. I already figured out its not really something I would want to GM; the specific implied play style of the system grates against the fact that I wish to approach it as I see fit, and I don't really care for the game's arbitrary implied universe choices simply because they are too limiting, and too focused on accomplishing a very specific style/feel of play.* I can accomplish this just fine with other systems and with fewer limitations. I guess it is now good to know that I feel the same way as a player, but at least I can safely say I am still enjoying the ride, even if its one I eventually want to get the heck off of.
*With this thought I suddenly realize that might be my real hang up with Starfinder, too. And pathfinder 2E to a lesser extent. The baked-in expectations of the game design just don't fit with my palette, if you will.