Thanks guys. Although he hasn't got the muscle "definition" to the level I'd like to see yet, with his build he might never achieve that. For now I'm very happy he has lost the majority of the excess poundage. He definitely feels a lot better, it shows in everything from his activities in the pasture (he now spends much of his time galloping around bucking and playing with my yearling) to how he rides (a million times more eager and forward - he's gone from having to drive him forward with constant leg cues to having to keep him in check and held back!) Improved hooves and training have a lot to do with that as well, but I sincerely believe his improved shape and not being so hugely obese plays a big part too.
Juna *lol* I was hoping with some weight lost he'd lost that "pony" look, but I don't think it's going to happen. He doesn't look that big without something to reference in the picture. He's only 16.2 ish HH, but he's built like a tank, he feels like a much bigger horse when you work with him.
Corinowalk - *lol* I know what you mean. I have a thing for chasing him around the pasture poking his rump spots.
Eventerwannabe - Thanks! He's no breed, he's a mutt. His dam was a paint/clydesdale and his sire was an appaloosa.