Both Hillrider and pierce: EXACTLY.
My last bike (2003, before my back gave out permanently) was a Harley Fatboy. HD owners routinely add to their bikes. Many of the adds have no value outside looking better or more fun. I don't even like to think about how many thousands went into it. I don't know about right now in this economy, but it was normal, it was routine, it was EXPECTED, that you would ride around on weekends visiting dealerships and buying bits and pieces. That you'd upgrade pipes and seats and cams and lights and.... plus engine upgrades. My next door neighbor worked his FatBoy down to new metal (tanks, etc) and the day he got it all complete, he turned to me and said, it's time to start again.
I'm not doing that here, I'd like the upgrades to be functional first. That's why I'm asking about what it takes to go from an 8speed to a 10speed. Using higher end components. If it also looks better, so much the better. I realize the Deore or XT or Ultegra isn't going to get me there faster or with less exertion or any of that. I'm looking for functional increases - better shifting, less jump between gear sizes. I'd love, in particular, to have a couple smaller jumps between 1st and 2nd and 3rd and 4th on my cassette. I spend a lot of time going uphill and spend a lot of my time on my small gear up front and the big ones out back. I'm new and not strong and going uphill in 3rd is a huge victory for me right now.
But if it looks better, well, hell yeah!