Their support suck, you have to wait for 1~2 days to get responses from them, they even didn't some time.
Their software is stupid , It removes customer's web access immediately the whos just cancelled but membership not expire.
Weak security, try this to see what happen if you are using opsbilling?
yoursite.com/cgi-bin/adduser.cgi?command=ADD&username=1234&password=123 4
also opsbilling declined a few valid cards...
I think I will drop them soon...
my
