This is interesting. Do you have profiling information about Rails vs. Django in general and Django on PyPy in particular? It would be very curious to look at it from a performance point of view.
My opinion is base on the following benchmarks : http://attractivechaos.github.com/plb/. This is obviously not a typical web application, but it gives a good hint on the performance issue.
Those interested in a C++ web app framework might consider wt (webtoolkit). It has a built in http/https web server and is thus plug&play for average applications. It is worth a look at.
Maybe. This means that the performance bottleneck is the database. Does this justify the use of a slower framework ? I don't think so.
I'll use an SQL db and CPython for the MVP, but I have an open road in front of me to optimize with NoSQL, PyPy, wherever it is required.
Note that there are many other parameters to consider, like ease of programming, toolbox richness, reliability of code, etc. The choice is up to you according to your weighting of theses parameters.
That would be awesome. Unfortunately it's quite hard to build your full app on pypy right now as it's hard to compile working database drivers and some other things you might want to use in a web project.
