Both Localphone and Callcentric have been working reliably for me, for many years (both incoming and outgoing calls). No lags that I have noticed. I use Localphone to make outgoing calls because it is much less expensive. A Localphone subscription of 800 minutes/month for outgoing calls costs $1.60. Unlimited incoming calls are free on both Localphone and Callcentric. I have Callcentric as a backup (never use), and when I have to send an outgoing FAX.
While using my OBi200 with Google Voice was free, when Google made some changes, I had to rely on Obihai to post a fix. Moreover, Obihai wanted to charge a yearly maintenance, and it appeared my OBi200 was being intentionally randomly disabled. Since switching to Localphone, years ago, there have been no issues, no glitches, just smooth sailing. It's been a pleasure. I do still use my Google Voice numbers. They transfer calls to my Localphone and Callcentric DID's.
Going to Locaphone was definitely the right move for me. I'm very very satisfied. Should you do decide to try Localphone, please sign up using this link so I might possibly get a small credit. It'll cost you nothing. Thanks.
http://www.localphone.com/?rb=g-ETNf1B4i76gTsjj-iP3fQIYAZUfCRTcvkGVW5UAN8