Cool, thanks for the thoughts. I'm going to go with Flask: my 24-hours-in opinion is that I can work with this, and it's got enough community support to make the easy things easy. I haven't done logins or much more with sqlalchemy-flask, but they seem good.

I'm a little worried the flask plugins are thin. As with anything where you have lots of flexibility, you can stub your toes if you don't know the "right" way to do it. For example, I tried to use flask-assets and pyscss to compile sass, but I found a bug in pyscss pretty quickly and had to back out and switch to the Ruby implementation of sass. Not ultimately a big deal, and the whole thing was up and running in about 3 hours.

EDIT: Ugh, more pain with Flask plugins. Flask-SQLAlchemy assumes you're going to declare models that won't be used outside of the web context ... so you can't separate your models from Flask. Annoying! Getting fixed here: https://github.com/mitsuhiko/flask-sqlalchemy/pull/250

So, anyway, that's what I'm going to do! Thanks for all your input!