I've been checking out some voip networks: les.net, inphonex, callwithus.com, and packet8.net.

Here's how I break it down:

Inphonex: Good luck working any kind of custom deal with inphonex. They refuse to allow you to spoof, or to set your callerid to anything that isn't a dummy number that they own. You can only attach the number of your DID to 1 of your virtual lines. It's amazing that they actually have businesses on board when they only have DIDs with two voip channels.

No asterisk support and no insights beyond what was available on the website.

ping sip.inphonex.com
PING sip.inphonex.com ( 56 data bytes
64 bytes from icmp_seq=0 ttl=49 time=80.758 ms
64 bytes from icmp_seq=1 ttl=49 time=81.133 ms
64 bytes from icmp_seq=2 ttl=49 time=93.139 ms
64 bytes from icmp_seq=3 ttl=49 time=84.449 ms
--- sip.inphonex.com ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max/stddev = 80.758/84.870/93.139/4.986 ms
You see that inphonex? It's called a ping. Quit telling your users that your SIP server doesn't respond to pings.

The SIP proxy server no longer accepts or returns ICMP packets. This is normal and does not indicate that the service is down.
Packet8.com: The sales people at Packet 8 have no clue what a channel is. I tried using the "virtual line" terminology to no avail. They don't have any prepay plans which is important for those of us who will use the service until the provider terminates us. I also wanted a prepay plan because I wanted more than one channel. They still don't understand. I'm starting to wonder if packet 8 is run as a real company.

Callwithus.com: Generally knowledgeable. It took longer, and it was often unpredictable, for a call to go through. I assume this is because of their routing scheme. The interface for placing calls was less cryptic than les.net and more usable than Inphonex.

Les.net: Complete opposite of the others. This service is clearly for expert users. After a few back and forth replies tech support stops. Sometimes you won't even get a response back.

I did have an issue where connecting to a box on the server beach network was failing. Server Beach took about 1week+ to resolve the issue and denied that the issue was there all along, despite the fact that it was replicable. The point of contention was that Server Beach refuses to talk to anyone about their network without a customer paying for a premium price for a trouble ticket.