Pros
There's a high ceiling as far as commission is concerned and they do a pretty good job of teaching you about the SDLC and various technologies- I went in knowing nothing about software development and was able to move into a corporate recruiting position for a top 5 tech company after a year at Apex.
Cons
Very heavily metrics based with weekly meetings with management to go over why you did or didn't meet your goals that week. This wouldn't necessarily be a problem, but management rarely, if ever, provided valid advice to which one could grow and become a better recruiter. Regardless of the week's performance the same advice would be given every week- stay later and cold call more people. Simply put- you peak pretty early as far as potential career growth is concerned here. Also, monthly recruiter meetings would be held to see "what needed to change" but nothing ever changed. They always devolved into recruiters venting about their issues, management listening and not making changes.