I don't really know the ins and outs of conformation like some on this board but I find him to be a pretty attractive guy. I think he has a lovely neck..his back legs appear weak to me or at least seem to lack muscle above his hocks...not sure if that is actually a flaw and if so..what it means per se but looks lacking in that area. Maybe someone with more knowledge can tell you more or even if what I see is a "flaw".
He is very lovely and looks like a sweet boy.. I'm not great on confirmation. But he doesn't have anything jumping out at me, other than he looks a little thin. But most TB's can be that way. Good luck with him if you decide to get him.
I like him! He seems like a sweet guy... very pretty. Could use some more weight, but he's a TB, and I'm struggling with weight on my guy too! Leasing him before buying is a great idea! Or maybe even a 1 or 2 week trial period? It's always nice to know it'll work out before taking the plunge.