are kindles worth it?

Or any similar e-reader. I want to read more but sometimes find it tedious to read in dim light and holding the pages down in windy conditions pisses me off. Does anyone own an e-reader and would recommend it? Or would you say not worth the purchase? I'm torn because it's nice having a physical book and i hate to go from staring at a screen all day at work to staring at another screen to read... but very convenient to just throw in my purse or what have you....