I love my Tipperary Sportage, but definitely try one on before you buy. Troxels and Tipperary's seem to fit fairly different head shapes, with Troxel being more round and Tipperary being more oval.
I find that all riding helmets are bulky, and I didn't notice any less bulk the time I tried ordering one of the $200-300 helmets. (This is one of my pet peeves... if road biking helmet manufacturers can use higher quality materials to create slimmer profile/higher ventilation helmets that offer the same amount of protection as the cheap bike helmets then why can't equestrian helmet makers do the same?) Some of the more expensive ones do have better ventilation, but that's not as important to me because it doesn't really get hot where I live, so I can't really speak to that aspect as much.