I'd avoid anything Samsung when it comes to android:
A new wrinkle in the update and fragmentation story emerged today. AndroidSpin is quoting an unnamed T-Mobile employee as saying that the carrier is being told not to release the Android 2.2 update (Froyo) to customers that own the Samsung Vibrant. The reason: to increase sales of the new Vibrant 4G.
The kicker is that the Vibrant 4G's specs are largely identical to the existing Vibrant devices. The only major difference (aside from name and branding) is that the Vibrant 4G sports a forward-facing camera and some additional multimedia features. It also is able to take full advantage of T-Mobile's HSPA+ network (which the carrier is branding as 4G). That HSPA+ advantage, however, has nothing to do with the hardware. The reason the Vibrant 4G can take full advantage of those speeds is because it ships with Froyo pre-installed.
T-Mobile allegedly has an update for Vibrant users ready to be pushed out, but is being asked not to push it out because doing so would remove a major advantage that the newer phone offers (increased data performance).
I'd also avoid Motorola if you like modifying your phone because they are hell bent on locking you out.