So far I am very impressed, as I was able to plug in the Obi202 and ObiLine with minimal setup. The ability to do basic configuration via the web portal on Obitalk is good, but if you want some serious tweaking and configuration you can use Obiexpert mode via Obitalk portal or the web interface on the device itself.
If you have no VoIP providers configured soon as you setup the Obi202 or similar products you could do free calls between devices. i.e setup an Obihai device say at your own place and grab another one at a relatives. Once these are both configured via the Obitalk portal on each account, you can do Obitalk free calls between them by dialing the Obitalk number that each unit is assigned.