I haven't tried it out yet, but I suspect dropping Python 2.7 is going to make tracebacks a whole lot clearer and easier to read. Right now, there tends to be a

I haven't tried it out yet, but I suspect dropping Python 2.7 is going to make tracebacks a whole lot clearer and easier to read. Right now, there tends to be a bunch of frames relating to `six`, which clutters things up. The new path based URLs look great - to me, the gain looks like readability more than anything (reading regexps at a glance isn't exactly easy, especially if they have named groups), and having built in type coercion for the parameters is a nice win too.