Ughh. TouchWiz plus "The Cube" is overkill personified. Neither of Samsung's customizations actually adds anything to the Android install on Behold 2. TouchWiz in this context basically just replaces Android's application drawer with Samsung's widget and app drawer, resulting in a more cluttered and confusing home screen - particularly if you're coming from virtually any other Android device in the world.
Cube is just a mess. Somehow Samsung's managed to make the user interface harder to use in exchange for bogging the system down with a layer of buttons and graphics. Seriously - what's the point of the Cube? It's hard to use and doesn't really look cool.
Otherwise, Behold 2 is a worthy enough competitor it's very similar T-Mobile stablemate, myTouch 3G. You get a touchscreen Android device that's slim and easy to hold but lacks a high-res capacitive touch display. Compared to mT3G, Behold 2 ups the megapixel count on the camera but lacks a trackball for easier one-handed use.