The best combo I've found was .148/.90 as this is the only relatively recent build that works. Everything else drops EDGE with 3rd party apps using TCP connections.
Keep in mind, though, that the .90 radio can be a little unstable (at least for me). I've had a few crashes and hangups here and there, but it's pretty much all I've got so I can live with it.
are u guys using t zones ?? im using the .167 build and after a few battery pulls here and there, i get stable data arrows. but i still have edge instead of EDGE.