Considering that Sharekhan has been around for a while, I prefer them over Zerodha. But in spite of certain glitches in their systems I still follow Zerodha and might use their platform in a few months.
in recent update in pi there are some bugfix and some problem appear. in my case "unhandled exception" error occuring during logging. any way sasonline alpha trader is more stable. but both pi and alpha trader have conflict with dartstock if installed in same system. and also both may have problem with trading softwares which use dot net 4 and abv