Well, here's my case:
I make $1250/mo. whether I fly or not. If my combined flight/ground time exceeds 60 hrs (soon to be 30 I hope) that month, I make $13.50/hr on top of that.
The downside? My boss is a nearly impossible man to please. I spend all day every day at work. Days like a few last week when the weather sucks, I sit there and do paperwork and keep track of the maintenance on the airplanes (which really could be a job in itself). I only get one day off per week, and if I take time off I have to work days off to make up for it (after the end of this month, I don't have another day off till the end of Sept.). Also, there's no benefits and I have to pay for my own charts and stuff (I hate FAA charts, but now that I'm poor, I've learned to read them!).
The upside? The pay really is not too bad (if I don't think about the total hours I spend there, cause then it only comes out to like $5.68 an hour), and days like today when I'm busy are great. I spent a total of about 1 hour in the office today, 1 hour at lunch, a few minutes moving airplanes around, and the rest flying- not bad for a 9-hour day.
When I first started, it royally sucked. I was hardly flying, and only then doing private work in the 152 and 172's. Now I've picked up some more students, and I'm flying the 182S and the 182RG as well and doing quite a bit of instrument work (in addition to checkouts, endorsements, BFR's, IPC's, and all that). So far this month I've flown over 20 hours, and its only the 10th, so I really can't complain. Except for not getting any multi time and the inevitably nasty winter ahead, I think I'm happier here than I would have been at FSI.
Sorry to ramble, but you wanted details...and I wanted to make the point that the FBO instructor route isn't too bad if you find the right place.
Good luck with your interview!