I can't say much abou the job prospects as they exist today, but I can share what I know.
Many carriers have moved away from reps and now market direct or through
FMO's. This is almost exclusively true for life & DI and to a lesser extent for health.
Rep positions (in health) open up infrequently. Most of the reps I know have been with the same carrier for years, while others move every 6 months or so.
Some guys (and gals) are good at selling themselves to a carrier to get a new position, others are not.
Reps have large territories, usually covering more than one state. If you do your job right it is almost a 24/7 job (although there are some reps who must be Gestapo on the lam . . . you can never find them).
Base pay is in the $40k range or so, could be higher depending on your background, products and level of responsibility. Bonuses can add another 50% or so to your pay. Most pay quarterly bonuses based heavily on new business.
Lot's of reporting and accountability. Crap flows downhill to you.
Paid health insurance is usually decent. Retirement plans and stock options can be nice if you stick around a while.
A good rep in a niche market can make $150k+ but those are few and far between. At one time the medical reinsurance industry was a $250k job with lots of perks and lots of bar time (as well as tee times).
Hasn't been like that for a while though.
Rookies can expect $50 - $60k. Get a few years under your belt and you might make $80k in a good situation.
If you want to be a company rep, you better be a good politician. When your boss leaves or is fired you may be close behind.
I really can't say about the P&C side. Above applies to mostly health reps.