I'd think an accomplished caster would definitely be able to realize the difference in a high-end rod and, for them, the expenditure may be worth it (or if you have $800 burning a hole in your pocket). I'm a hack (although blindfolded I could definitely tell you which end of the rod I should be holding) and if I had $800 to spend on a new rod (I don't), I'd be better off putting it in some casting lessons so that I could better use the rods I have.

Regards,
Scott