I have a Haflinger gelding. I can attest to what most of the others posted. He is calm, gentle, and wonderful to ride (we mainly trail ride and I have yet to encounter anything on the trail he spooked of/ balked at/ or refused to do).
He is stubborn, lazy, pushy and in your space, though. He tries to get into your pockets, saddlebags, tack trunks, etc...looking for food. He's also pushy when leading him. However, my gelding is a complete pushover when it comes to other horses. He's always at the bottom of the pecking order in the field no matter who he is turned out with.
He had been foundered before I got him and Haffies do tend to have weight issues so we have to be very careful about his feed and "ease" him onto the pasture each spring.
That being said, his few quirks do not outweigh the fun I have riding him. I've ridden so many hot and spooky horses in my life that the pushy and laziness are a welcome change :)