Testing for packet loss on the OBi>OV connection? No - but packet/jitter testing in general using visual route, yes.
[edited to add... I reverted back to the delay between caller and recipient during a phone call from here on - sorry]
I saw your post earlier that said 200-400ms to a cell. So if both caller and recipient are OV, and are both on the high end of that range, that's a very perceptible 1 second delay.
I'm in central FL with FIOS (50/25 package) - and my connection has always been rock-solid. I've been using OBi w/GV for several years, and never saw this kind of delay... That's really the only reason I suspect it's OV - or specifically 2 x OV.
I'm all ears on how and what to test.