I recently gave Pylons and SQLAlchemy a spin. I mainly wanted to check out SQLAlchemy so that I could evaluate it for upcoming projects. Well, my opinion is that it is wildly flexible and, therefore, came with a steep learning curve. Pylons wasn't too hard to grasp although it seemed sort of arcane at times. I genuinely liked Pylons though.
This has been a disappointing experience for me. I wanted Pylons and SQLAlchemy to be fantastic so that I'd have a compelling reason to come back to Python full-time from Ruby. Not the case, I'm afraid. Looks like I'm going to be spending more time in the Ruby and Ruby on Rails camps in the future.