We've had it for maybe 3-4 months and so far so good. There are 2 disadvantages that I could see: 1) if power goes out, you have no phone 2) if you dial 911, your address may not appear on the screen as it would if you had traditional phone service (I believe they're working on making this happen, but I'm not clear on the specifics)
The other thing is that when we switched, you couldn't bring you own phone number. I believe that's changed, but it will cost you a one time fee ($30 is the number that pops into my head, but I could be wrong).
We've had clear connections, no lost calls, nothing like that. The service is excellent that way and it has saved us around $30-35/month compared to what we were paying with Verizon.
HTH! Lori