Thinking of a web service entirely built on top of MongoDB, while I am pretty confortable with PyMongo, I would like to know if you guys have any positive or negative experiences/stories about either of these ODMs: MongoKit, MongoEngine and MongoAlchemy, the latter having a Flask specific package "Flask-mongoalchemy".
I use MongoEngine with flask no problems. We've written (collected resources) which include wtform support and flask-debugger support as well: