Was he gelded late? He has a really thick neck....nothing compared to Sundance's neck, though lol! Ok, here's my critique:
*I can't really tell how his head joins his crest without a pic with his head up...
*He has small-ish haunches
*the distance from the front of the stifle to the point of the hock is longer than from the hock to the ground
*high stifle, but a little too far back (good with groundwork, but will have no extra extention if doing jumping)
*nice square butt
*hock is even with the chestnut on the front leg, which is very good. A horse with too-low hock can't move his hind foot forward as efficiently and has a shorter stride. This reduces a horse's ability to travel with maximum leverage and power. A horse with a too-low hock has less thrust from the hind leg and therefore less speed...so you want a nice alignment from the chestnut to the hock.
*Good pronounced topline; not too round
*looks as if his downhill balance is desirable (common to sprinters)
Overall, he looks great :)