The service is great. I pay $35 for unlimited calling across Canada and the US. It's a no brainer for me. Working from home? No problem, I make all the conference calls I want without tying up the home phone. Need to phone mom long distance? No problem. Working from my girlfriend's place where there's no landline? No problem.
There is the occasional issue. Sometimes (rarely), calls drop. Sometimes (very rarely) there is a number somewhere in the US I can't call. Honestly the biggest problem I have is that my number comes up weird on call display, so there's times when people I'm phoning don't answer because they think I'm some telemarketer, but really that's just my own fault for not shelling out $14 for some Skype credits so they can send an SMS message to my cell phone to confirm that they can use my cell number for call display.
Really their problem is they need to advertise better. When I tell people what I pay for my service, they immediately say "Holy crap that's cheap!" Most people just don't know it's out there, or if they do, they think it's only for Skype-to-Skype calling, and don't know you can call regular phones with it.
It would be nice if they had Skype-In support here (Canada), but really for what I'm paying, I can hardly complain. I easily am recouping in long distance savings what I'm paying out. It is not very hard to rack up $35 in long distance charges in a year otherwise.