I have been a VoicePulse user for some 9 plus months. One thing I noticed is unlike POTS, which provides duplex communications links (meaning both ends can talk/hear at the same time), my VOIP is simplex. This means if I start talking before the other side has ended their speaking they hear nothing I've said. The biggest disadvantage is noticed when participating in a conference calls, I cannot say anything until ALL other callers are quiet, which is not often. It causes me to carry the discussion back in time to add a point others thought were finished.
Secondly, my experience with VoicePluse's tech support is not that good; they often do not fully read an email stating the problem and will respond asking for information already provided. The first time I did not respond immediately since I had already given them the requested information; they then declared the problem fixed even though they took zero action to address it.
Overall, VOIP is fair to good, but I see it working only as an supplement to normal POTS.
Lou Jahn Info Partners Corp