I have first-hand experience with a BI-ish system, squarely targeted at the enterprise and doing quite well there, that we wrote using Django and a whole list of open source components.

We did run into some resistance initially, because our stack is almost the opposite in every way of what our enterprise colleagues are used to. However, our development velocity, especially around analytical features and just in general, has made a most gratifying impact.

(I have to add that the 5-man dev team we have working on this is stellar. It's hard to determine scientifically what the interaction is between team quality and the choice of a Python-oriented software stack. See Paul Graham's essays for more discussion on that point.)

In terms of support: There are many highly professional often boutique software agencies that can support Django systems, if you're not around. To my mind this is even better than the normal commercial support you get from a different vendor for each different component in your commercial enterprise system.