I have a feeling I can't be farked with it. I'm running a 276c and since it's only available on data card and hoops I'd have to jump through to load it on my unit are both too many and too high, I'll probably just give garmin topo a go.
A quick read suggests it's pretty much like v2b apart from having tracks come in at wider zoom level and some other changes which haven't convinced me to upgrade.
No routabity is the nail in the coffin. I have almost $500 worth of maps on the unit with city nav and oztopo, If oztopo v3 was routable I would have given it a go. As it stands now I'd have to spend $300 to upgrade both mapsets if I use oztopo vs $200 to just use the garmin topo.
Makes the choice much easier...