I ride english (dressage, h/j, english pleasure, trail), a few things bother me but it can be applied to either displine. I hate when people ride peanut rollers, who are on the forehand or behind the verticle. Your might think you look good, but its not how anyone should be riding. I am not a fan of leverage bits, I see more of that in western. Unless you have soft forgiving hands you can mess up a horses mouth. I don't like those western "cowboys/cowgirls" who think they can break and ride anything.
I really like to watch wps classes at the shows. Those horses are gorgeous and look so comfy to ride. And I've always wanted to try to ride a bull. I like how in western shows you try to look as flashy as possible, where in english you have to pretty much blend in and look discrete. I want bling on my saddle!