While there is no doubt that voip.ms is a great provider, I wonder how we get with those " occasional call quality " issues to 100% call quality rating. Nothing personal, I roll my eyes by about a half of the reviews here because of this super optimistic ( or pessimistic) approach.
I couldn't give them a 99.999999 rating. My call problems are occasional and they are quick to resolve. It is VoIP after all and it is for pennies. I can't expect a SLA of 24/7 guaranteed uptime without paying for it.
I've even had call issues with my Bell POTS line and had to call repair, but I would still give POTS a great rating too.