I think the difficulty is that I don't really know if I'm happy. I think I am, but I feel like I have insufficient information to really know, hence the post.

Is the $50k number you're citing the upperbound of what an early-hire should expect to be paid? Looking at ackwire, I see the vast majority of the engineering lead positions are for cash compensation amounts much higher than that. (viz. http://www.ackwire.com/level/lead )