For those that are wondering...
I switched to Vonage some years back because of the ridiculous pricing my local phone company switched to. Vonage was about half the price (basic service, 500 minutes a month).
I switched to Ooma just a year and a half back. I bought the Ooma Hub and a Scout (expansion module) from Woot (thanks!) and haven't looked back. I pay $3.47 a month for my service, plus $9.99 a month for the Premiere package since I have two phone lines.
I just switched to a yearly payment on the extra package ($99) but before that my monthly bill was $13 and change, still less than what I was paying Vonage for 2 lines (was $24 each I think).
Call quality is good and clear, no complaints from my wife or people that call us. I recently purchased 2 more Scout modules so I can expand the system a bit better. The main house phone (Line 1) rings to the Hub which is upstairs in my house and also to 2 of the Scouts - one in the basement family room and the other in the garage/workshop. The third Scout is configured for the second line (Line 2) and rings in my home office.
The reason I got the additional Scouts is that, unlike Vonage, the Hub and Scouts (and the Telo FYI) have a visual indication of voicemail, and they function just like an answering machine: push the Play button and listen to your voicemail, delete it, rewind/FF, and also one button Do Not Distrub functionality all without picking up a handset. The extra scouts just make things more convienent, and since I got one extra as a refurb for $20 and the second extra free for switching to yearly billing on the Premiere package there was no reason not to get them. I'll probably end up taking the Scout from the workshop and putting it on a shelf as a backup unit as it doesn't get used all that often, but only time will tell.
Regardless, the Telo functions in a similar fashion, just without the expansion module like a Scout. Instead (if memory serves) you can get additional cordless handsets to go with it and you end up with the same functionality.
In my mind, there is a 100% feature comparison between Vonage and Ooma. Both have websites where you can access voicemail and settings, both do call forwarding and such and everything, but for me the Hub and Scout combo can't be beat since it is so much easier to seperate out phone lines based on function and such.
I'm on Ooma and I'm not gonna leave unless I can find something even cheaper (which currently is highly unlikely).
The Hub and Scout are now becoming a discontinued item, but you can still them them in online stores and eBay both new and used for cheap. Still the Telo unit is hard to beat with the built-in cordless phone functions.
These units sit on a wired network connection, and even weak broadband speeds (384K Express service from Comcast cable) work great. I haven't dropped a call yet, no one has had a problem calling me, and when my cable is out (and Internet along with it) Ooma is setup to automatically forward to a cell phone instead (just like Vonage does). I love it, all of it.