I haven't tried them out in birding conditions, but a brief comparison with my old pair does reveal sharper colors and better resolution. They are definitely a little heavier than my Nikon Actions, but I can hold them easily with one hand.
The optics4birding review was dead on about the poor fit for the rainguards - if you prefer a shoulder harness to a neck strap (as I do), you're going to have to be careful not to lose the guards while walking. I may try to attach them with a short chain or something, since I want to keep my lenses protected.
I'll post my birding experiences with them on Monday, as I will be birding all day on Saturday with them.