Replying to Heated socks?

I am considering buying a pair of heated socks instead of adding heat to my footbeds as it would be really nice to be able to use them in both my touring and park boots and also normal shoes. Problem is almost everyone I ski/work with have heat in their footbeds but no one seems to have tested heated socks so would love to hear your experience with them. Especially wondering how durable you have found them, how they fit compared to normal ski socks, how often and how you wash them and of course if they keep you warm. Was looking at the Zainer Feet Heat socks as they are on sale but haven't found much about them.