I used to say that a VF would be a requirement for any camera that I'd buy - but after getting a GRDIV, and just recently, a GR - and I'd say I'm pretty happy with just using external 'dumb' finders on the hot-shoe.
But, there are times that I remove the external finders because I want to go out with a camera in my pocket - so I leave the VF at home, and shoot off the LCD - I'm only just getting used to it, but I find that I usually do this in 3 different ways -
1. I shoot with the camera up to my face, and the LCD about 8 inches from my eyes. So, it is still kind of like shooting with a VF, haha. You still get to "hide" behind your camera.
2. Hold the camera out with two hands, usually stomach and chest level. (Not shooting from the hip, but still looking at the LCD) (I usually do this for 24mm and wider) (Think of it as crouching when shooting with a VF, except you just look like a tourist)
3. Hold the camera out with one hand, and thrust/extend my arm out towards the scene. (I usually do this if shooting close, or in really really crowded areas) (i.e. I bring my camera closer, instead of bringing all of myself closer, since it's less 'intimidating' - I hope that makes sense, LOL.)
As it is, there are still times I miss shooting with a VF - but I do also find shooting without a VF pretty liberating, for some reason. I don't know if that's partly due to the smaller cameras as well. But I do feel more "fluid" when shooting with just the LCD, especially when shooting in a crowded area. Biggest problem with shooting with just the LCD, in my opinion, is that it's sometimes hard to see details - i.e. facial expressions etc..
Cheers.