Advice needed on using hobbit across WAN

From network speed point of view, what kind of ping response time is not suitable for hobbit client/server deployment ?

I have one overea site that answer ping test steady at 300ms.

Does anyone have experience on deploying hobbit across WANs over country ?

I know using proxy is an alerternative but what about direct report over a pipe with 300ms ping time ?

T.J. Yang