Yeah, as with Chris, small eyepiece works well enough with glasses, large eyepiece really gets in the way. I don't find it indispensable in that I used to shoot a lot with it and without it, but I don't think I'd want an RX1 without the option to use it sometimes. Occasionally it's nice to take it off and go really small though, and Sony's "sunny weather" setting (or whatever they call it) for the LCD brightens it up enough to see well in almost any conditions... I've seen them used in the $350 range whenever I last looked, but that was a while ago, so maybe a bit less now?
-Ray