Neither me or my mother went about buying our horses (we both are still on our first horses, but have had them several years. Shan and I just had our 7 year anniversary!), neither of us went about buying our horses the conventional or smart way. Both of us just 'clicked' with our horses, and knew that they were the one. There was no talking me out of that green mustang mare, I was dead set and it wasn't smart at all. Thankfully, we blossomed together!
We looked at several horses for my mom, a few years after purchasing my mustang. She clicked with Belle, and that was it. Bought from a down and dirty horse trader who was a very strange lady. Not in top condition at all. Our trainer evaluated her and from the little tests we put her through, thought she would be fine. Not trainer's first pick for mom, but said she wasn't dangerous. Belle was nervous, a bit touchy, diving for hay scattered on the ground because of being underfed, but we had a good feeling about her and she did what we asked.
We certainly took a risk, but she turned out to be an absolutely amazing horse. Mom loves her and could not be happier with her. They trail ride for hours and hours and Belle has proven herself time and time again. She actually takes care of Mom. Mom did fall off twice the first year. One was a tack malfunction and the other time Belle bolted (she got spooked), mom didn't have a good seat yet and fell off. Both times she was fine and Belle was fine. Belle has turned out to be very non-spooky and a very solid trail and arena horse.
Point being that I'm not so sure there is a 'perfect right off the bat' horse available to buy. I'm not sure I've ever met someone who didn't have little ups and downs (or sometimes big ones!) with a new horse. Its just part of the process of getting to know each other. A lot of horses come with habits that you don't like but the previous owner didn't mind or encourage. Different people, different horse handling methods.
Well, my simple point, thing to remember, is that IMO the mind/temperament of the horse is the most important thing to consider when buying a horse. A more timid rider does better with a follower type. An experienced rider who is up to being severely tested will do well with an alpha horse.
OK, I'm done ranting. I'm as good at being brief as you are!
"You can do something wrong for thirty years and call yourself experienced, you can do something right for a week and experience more than someone who spent thirty years doing the wrong thing." ~WhattaTroublemaker