I had a similar experience working with Jifty. I found the transparency on the database layer very good, and was able to get a lot of mileage out of that. When it came to the actual web code, however, I found Jifty getting in my way more than helping me out. Most of our bugs tracked back to a poorly documented user permission structure. After several days spent crawling through Jifty looking for what was set wrong, we eventually decided to strip out Jifty and build up a simpler system based just on raw Mason. Even factoring in the conversion time, it was a net gain in productivity.

YMMV of course, and it should be noted we were working on a fairly simple application where rolling our own interface from scratch was not that big of a deal.