Unfortunately, I can't give a more experienced critique, lol, but here we go. By the way, you have nice horses...
I also like his front end. It all fits really well together- lovely shoulder, and although this may be more of a personal preference, I think his head and neck are lovely. His front legs look very nice, I'd say they're perfect, although he looks a bit light in bone and his legs look like they're set a little far under his chest (pigeon breasted??). Nicely angled, short pasterns all around, nice short canon bones and low-set hocks. His back looks nice and short although he is pretty bum-high. His hip looks okay to me, although he has a very steep coup. His back legs look a bit straight to me, and/or sickle-hocked. Not positive.
Hopefully I did a good job with the critique- Overall he is a very pretty guy, although a little chunky, lol!
Nice solid old time type Quarterhorse. VERY substantive with good bone and good muscle. Back is a little long and butt is a little high. He is a bit sway backed.. and could be helped by trotting up hills and over cavaletti. Croup may be a bit steep and his point of shoulder could stand to be set a bit higher opening that angle a bit more.
That being said, this is a really solid horse. Looks a good bit like "The Ol' Man" and I like him quite a lot,