HagonNag, before I decided to purchase a horse, actually many years before, I leased two horses that were used in a summer camp program.
One was a very well trained and behaved gelding. A real joy and gentleman. The other, not so much. He tested me on every level in saddle, was fine on ground.
When I looked at them prior to leasing, they were both terribly underweight and very quiet. Upon bringing their weight up with free choice hay and sweet feed (didn't know better back then), one remained a gentleman, the other as I said became a handful.
On the whole it was a good experience and I wouldn't hesitate to recommend to someone to look them over.
Be the kind of woman that when your feet hit the floor each morning the devil says, "Oh crap, she's up!".