When i was in Nepal for 6 months,my wife used every type of calling card possible.It was extremely frustating for her.It used to take a really long time to connect and if it was a call to a cell phone in Nepal,the calls used to drop every few minutes.It got so bad,i had to start calling from there to stay in touch.
After i came back,we looked into what service was good and about 8 months ago a friend told me to try stana card.I tried it and found it to be pretty reliable.Thats how i have been staying in touch with my folks back home.
Although i admit i do not use it that much because most of the time my folks call at a predetermined time,since it is so much more cheaper to call from there.
But when i do have to call,i find that stana is quick and reliable.
This is ofcourse my personal experience and other users may have their own stories to tell.