Unless the OP will be getting a significant portion of preferred stock (viz. it won't be clawed back and it will receive money in the exit), I doubt that evaluating the company as an investor would is a good idea. Piggybacking on the YC filter would mean joining a company that already has VC money, so potential employees should be doubly careful about their percentage of stock and their stock options.
It would be much more self-serving for an employee to read and consider information aimed at employees. A good article on this is http://michaelochurch.wordpress.com/2012/07/08/dont-waste-yo...