I had the X-E1 for one day, took it back to the store and came home with the X-Pro. So I guess I looked back. The difference in size and weight between the two wasn't significant to me. Yeah, the X-E1 was smaller but not that much smaller. As most everyone else mentioned, it's all about the hybrid OVF/EVF viewfinder. With the rebates, the dif between the X-Pro and X-E1 plus two lenses was only a couple of hundred dollars. Ray decided for me that the OVF was well worth a couple hundred dollars and now I have the X-Pro. The OVF, I feel, significantly improves the handling/performance of the camera, especially coupled with how and what I shoot (photojournalism type stuff). The OVF eliminates the slow refresh rate of the EVF, the bright lines automatically adjusting per the focal length of the zoom/lens is wonderful and it is always there, available and useable in all lighting conditions.
Gary
PS- If you think the X-E1 is sexy ... then the X-Pro with it's working rangefinder all decked out in midnight black, is pure porn. The closest thing to a Leica other than a Leica.
G