Okay---seems either the other posts tried Voicepulse early on or are in limited usage areas.
I have been on Violcepulse now for over 6 months---the good, bad, and ugly of it is:
yes equipment arrived within two days and was up and running within 5 minutes.
However. there are very frequent periods of outage or inability to use it!
Either callers get nothing but some tones or the line signals busy sometimes for hours even when I am not there and could not possibly be on it! Despite the fact that it "should" have call waiting anyways and does not. I take that back once in the six months it did actually work!
There are frequent periods when it is dead (nothing) for me to dial out on not even a dial tone or I get the dreaded busy signal when I know the callee is not on the phone or they have call waiting and I should not be getting a busy signal either way!

Tech support does respond within a couple of days to your emails and the number they give also provides the same support, you give them your equipment life history and hardware and they give you a list of things to "try" none of which has anything to do with the problems callers to you
should be experiencing but you try them to no avail none the less and then it falls by the wayside...apparently forgotten and certianly not FOLLOWED UP ON BY VOICEPULSE SUPPORT after that!

As far a quality goes the best I can hope for is equalivient to a bad cell phone conversation. As a matter of fact I have resorted to basically using the call forwarding to my landline so I can carry on conversations with my callers. I call them, repeatedly yell for them to call me back and answer it on the landline...only good thing I get from it is my callers don't pay longdistance!
My advice; get it only as a secondary to your landline to cut down on long distance calls, get the area code for where ever you call or your calls come from or to and have it forwarded to your landline or theres'!
NOTE! Even this does not work for overcoming the busy signal and nothing noises your callers frequently get when calling you!!!