I had 3mb dsl from a local ISP for about a year and voipo was flawless. The minute I switched to comcast I started having problems. I havent complained to voipo because I've done my own trouble shooting and usually when a call gets dropped, messengers sign out, and some times the tv even goes out for 2-3 seconds. There are never any dropped packets but I have seen some 3000 ms ping times which I know isnt healthy for a voip phone call.
But its like I tell people, a few dropped calls are worth the $500 a month in savings.
On my dsl, voipo was as reliable as any landline service.