I have interacted with many discount brokers before opening account with SAS. I already have account with other discount brokers like zerodha.
Service - wise zerodha, rksv etc are in top bracket I guess as they have bigger and better customer care team with threads in TJ etc. However SAS also has a blog in their website to answer client queries. Their email interaction has been good so far. I will post other issues as and when I find them.
Hope this helps.