It depends on what I am doing as to what I use. If I'm doing anything serious, I will either use full splint boots, or polo wrap my horses legs.
I am very cautious when it comes to my horses legs.
But if we are doing gymnastic exercises or anything under 2'6-3' I normally will use open front boots if they are either young, inexperienced, or over-step. This way it protects their heels but will allow them to feel the pole if they hit it, which hopefully will make them pick up their feet a little better next time.
Otherwise, I may not use boots or wraps. I don't want to 'over protect' their legs, but I want to make sure they don't injure themselves either.
Then again, it really depends on the size of your horse compared to the jump. If you are jumping a small pony over 2'6, those jumps are big to the pony, so I'd boot it.
Haha, it all depends.
Oh, & I prefer fleece boots :)