Hi Gidget! I think your horse doesn't know or care what sort of saddle is on it's back. But, there are more differences in E to W than just saddle, as you well know. The main being the amount of rein/bit contact differs between the two.
I think you have to see how your horse fits there. Is she really troubled by riding on contact? And if so, is it just because she isn't used to it, and you can train her into it? You are right in that jumping is harder on the horse, and if a horse has any back issues or maybe tender feet or other pain issues, it won't enjoy jumping and will demonstrate it with pissyness.
If Gidget is always pissy, and you're sure it isn't a pain issue,, then I guess you just have to pick the lesser of the pissynesses and go with it.
She sure is a character, isn't she?