Pros
First of all, it's a real US company located in Bay area, not like a fake "staffing companies" from India pretended to be an "American companies". Skyrocket recruiters are professional and do understand what we're talking about, I mean programming languages, technology stacks, frameworks etc. - this is pretty rare these days! Second, they aren't cheap and never try to cheat on you with W2 contract rates or FT salaries, they are always provide you a fair market rate, I really appreciate that! Third, Skyrocket never spammed or blackmailed me, never ever! All emails or calls I received was about new opportunities (a real ones, from the exclusive Skyrocket clients, not a positions can be found on job boards and popular websites).
Cons
Can't remember even one! They are definitely good and not annoying.