It's just "weird" to ride english after being a western rider- but you get used to it pretty quick. The only thing that bugs me is that if I need to scratch my nose or something I have to juggle reins (which, at least, I'm good at from riding western) It was really weird in an english saddle at first, and it took me a lesson or two before starting and stopping suddenly didn't off balance me a bit. I have really short legs, though, so right away I appreciated that my leg aids didn't have to get through so much leather and padding to communicate with Regal.
I think it's harder for a horse to transition than a rider. I am really glad I've been working with a pro trainer through the transition.