On AngelList I was applying to companies myself and did two interviews with locally based startups. One of which was basically hipster central and turned me down after the interview because their highest developer pay was lower than my previous salary. The second one I interviewed at was Hopper, which I abandoned because their interview process is too long and drawn out for a startup. If I wanted this experience of probable rejection after months of interviewing, I would just apply to Google.
The only impression I got was that LinkedIn lead me to real businesses who have an immediate need for devs. AngelList has startups with an inflated sense of self-importance who wish they were in San Francisco.