My experience (mostly on the hiring side) is that an in-house recruiter is indeed trying to close you if they think you'll be a good fit (they're measured/bonused on metrics around their job, after all) and third-party recruiters are just interested in closing the deal and you staying 90 days.

As a hiring manager, I can't recall ever being influenced by a third-party recruiter as they "love" all candidates at a rate equal to 30% of the candidates' first year comp.