The only gripe I'm facing is, Calls made by Viber doesn't match my contacts on the default HTC Sense dialer's call history, i.e. Shows "Unknown" instead of the Contact's Name.
It however shows them contact names correctly on the Viber's Call History.
Other than that, its quite ok for now, haven't uncovered any problems yet.

PS. Using HTC Desire on Reflex S 2.1.7 (latest atm) Custom ROM. HTC Sense version is 2.1

This post has been edited by Dragonflyz: Jul 22 2011, 03:35 AM