Your snow pics were beautiful and Patty is looking good, Kim! I'm looking forward to seeing the foal she's hiding. I don't have any babies coming this year - still haven't really made up my mind if we are breeding 1 or 2 yet for next (shouldn't). I MISS the babies.
Ahhhh - the "ye ole Merry Chase"... Yes, we know that one well.
It isn't that hes' changed since being gelded - it's that he feels better and now has the energy to MOVE since you've brought him to the optimal (or getting to that point) condition. He couldn't do it before - because he simply could not.
Horses that seem tame and/or "trained" often are not but you can't always tell when they are way underweight and just struggling to survive.
You'll just have to learn his personality and maybe get some handling help to learn the subtle body language that can make a huge difference in catching him. I've been around horses/ponies a long time - and I'm still learning that! I have a tendency to be too aggressive w/ my body language. The 3 mares that I've got now - let me know all about it (can't get near them!) when I'm wrong or too "forceful".
In the meantime, venting is quite alright, LOL!