I'm from the UK and found out about this via EWB-UK (Engineers without borders).
I was hesitant about a few different things before going (India is very different to Europe), however everyone I met (fellow participants, staff at cse abd even just people on the street) were very friendly and I soon settled in.
Therefore if you think you might like it, then definitely apply!
Also I was the co-editor of the magazine in 2014 (summer) and I advise you to pick a large role as although it's more work it's a lot more fulfilling.
What would you improve about this program?
Hmm, maybe a little less specific to India (eg we has a couple of lectures that went into a lot of detail about Indian environmental law), aka generalise more.
Also the more field trips the better.