Fluid changes do make a difference, not psychological... especially tranny and diff. Plugs make a world of difference, and adjusting valves will make a difference. For a few days, it will feel brand new again.
And I can't wait to hit 150 - 170k (currently at 110) when I get to do a whole head job... woo hoo. That will certainly make a difference
So what fluids did you go with, or did you just get everything done at the dealer?