I started using web2py about 6 month ago. I choose it, because I wanted to move from PHP to Python, to have a more object-oriented approch because of the language featrues of python.
The all-in-one approach of web2py is really amazing and makes the start very fast.
As a former symfony user I soon started to miss Components and Forms that aren't dependend on table structure.
Just with a simple registration form, I could not find a way to do the Form DRY. For me the real bugger was the form validation. I forgot the details, but I ended up with having form validation in the forms itself. Because some thing just didn't work else.
Also the naming concept of capitalised words with that lot of repeated chars is just not my thing.
dba.users.name.requires=IS_NOT_EMPTY()
dba.users.email.requires=[IS_EMAIL(), IS_NOT_IN_DB(dba,'users.email')]
dba.dogs.owner_id.requires=IS_IN_DB(dba,'users.id','users.name')
dba.dogs.name.requires=IS_NOT_EMPTY()
dba.dogs.type.requires=IS_IN_SET(['small','medium','large'])
dba.purchases.buyer_id.requires=IS_IN_DB(dba,'users.id','users.name')
dba.purchases.product_id.requires=IS_IN_DB(dba,'products.id','products.name')
dba.purchases.quantity.requires=IS_INT_IN_RANGE(0,10)
Sometimes the names have to be in quotes, sometimes not ... and if I looked at the examples or sites already made with web2py, I really didn't see that big step forward from using php.
I recommend you: Look if web2py works for you. It would be nice, because the community and especially massimo (the creator) are very helpful and nice.
Also you have a much quicker start, than with django, easier deployment and less hassle if you change your database models.
