Oly,
I made my RV4 more comfortable by moving my front seat back a little - 1.5" at the bottom (hinge), and 2.5" at the roll bar. This gives me a little more seat back tilt plus some legroom. It's pretty comfortable. I'm not concerned about the back seater, who now has no controls - still a pretty neat airplane to give rides in. That being said, I am building another RV8. Considering the wrap windshield. I built a Showplanes fastback on my first RV8, and it was great, especially the visibility, but it was more costly, and time consuming. This one will be a standard slider canopy, unless I can figure out how to build a slider fastback for the same price(roughly). The speed slope looks cool. Combined with a FB, I think you gain a couple knots (plus it looks even more cool).