While I can say that I am ALWAYS learning new things as a pilot, I can say that the number of things you will learn going around the pattern as a CFI for 2000 hours may not necessarily make you a proportionately better pilot than you were at 700. It'll make you better, but perhaps not so much that it's worth the time it takes.

There is a certain breed of young, low-time pilot being hired as a result of the current hiring climate that offends some folks. Speaking very, very broadly, the stereotype of which I speak have never had a non-flying job (or maybe ANY other job), and are difficult for those of us who are a little older, sadder (and yes, maybe a little wiser) to get along with. Part of it might be jealousy, but I think most of it is a straight-up difference in maturity (no matter who you are, you're not the same person you were 10 years ago, and most of us don't want to go back).

When a young guy on career month #4 sits down in the right seat of a jet and bitches about how life's hard, they are running the risk of annoying people who have lived and worked and sacrificed for a while to get where they are. If an FO does his job well, gauges the cockpit climate properly, and listens before talking, he or she will almost never be perceived as "low-time." If you are young and low time and have given something like the "cockpit climate" some thought, you're probably not the type to set off discontented grumblings.

If you run into a captain who's bugging out about low-time pilots (they are rare), keep your mouth shut. If you just can't do that, ask them sincerely if they had been given the opportunity to go to a 121 operator when they had 700 hours, would they have turned it down on principle so that they could acquire additional Cessna 172 experience? Be good at your job before you say anything, though.