I like a SA GPX WF4F on my 490-2 GLX Classic . . .same vintage and similar action to your XP.
What is your required cast length? The GPX is a half weight overlined. Using the 5wt version on a 4wt will likely overpower the rod if you are casting more than 30 feet.Valid point. I'll be getting a 3 or 4 weight trout classic for small streams. Since my 4 weight is a 2 piece it will be best for floating rivers, lakes, and Rocky Ford.
I'll get a SA GPX wf5