I have been with
Voip.Ms for many months or a year and have gotten accounts for others.
I am happy with the service. When they have an issue, I get multiple emails warning me (just as you would hope with other companies).
They have multiple extras included to manage and forward calls. They have two rate structures where you can use cheap or premium routing. You can choose on a telephone call basis also if you need to use premium to a specific location.
You can easily limited what countries can be called. The "gotcha" is Hawaii is considered international :-)
If you want, you can also set up subaccounts and assign one to a family member. They can be made to pay for their own calls if you want (and yes, you can bump the price up a bit and charge them a premium to cover that expensive comic book they stole while you were at camp).
You can (as with other companies) get an INUM and use that for testing into the account from places like GoogleVoice.