honestly you can find it yourself, but for the sake of recaps:
- small or none support for application's unittesting. up until now there have been a few experiments but no one landed in the code
- routes_onerror can be used to cook something that will display the error right away, and I'm not so sure it'll work fine but there was an extension for google chrome or firefox that opened errors right away. That being said nobody is telling that the admin app can't be improved, it's an app and totally customizable
- DAL is certainly improved in 6 years but still it won't ever be an ORM. That's the whole point of choosing a DAL over an ORM
- we can't faster IDE adoption but there are a few that work fine with a little trick (web2pyslices holds the recipe)
- web2py is completely multiprocess-aware. I'm not a big user of other frameworks but they smell less multiprocess-friendly than web2py (e.g. the cache and sessions). Because of those choices it's probably a little slower in single-process performances but nowadays production always requires multiple processes.