Long term, Python is the way to go. The python interpreter is much more complete and it is possible to install modules on a switch. I spent a lot of time learning tcl/expect but I am moving on to python. It's a lot more fun and a much more marketable skill.
The JSON-RPC-Python scripting option where the python runs on the Netsight server and leverages a JSON interface to the EXOS switch looks very promising but doesn't seem to be well documented or much discussed.