I have flown first on flights only slightly longer than that, but only when I've either found a really good deal or it's been a complimentary upgrade. Agree it's not really worth it on flights that short. Even on longer flights, it can be so expensive it's hard for me to justify. I like the "in between" class, it's Comfort Plus on Delta, other airlines have the same thing under different names. That tends to be a more reasonable expense for me to justify, especially on longer flights.