This was originally going to be a comment on the previous post, but it went long and got deep, so I felt it was worthy of its own entry. You might want to read this about Fridge Logic, and the comments, before continuing here.
I am baffled as to how non-fighter abilities such as assassination, backstabbing (supported by move silently/hide in shadows), open hand damage or spells (sleep, burning hands, magic missile, web, fireball, cloudkill, heat metal, cause light wounds, cause fear, call lightning, produce flame, spiritual hammer, chromatic orb, hypnotism and so on) are somehow not classed at the primary gains where it comes to non-fighter classes. I haven't heard any mages getting excited at 5th level because they can at last use infravision. I don't deny that non-combat abilities do accrue at gaining levels, but lets be serious about this - it is the combat privileges that players slaver for.
It is disingenious to argue that a player's hit points do not increase their likelihood of surviving through a combat, or that players do not take advantage of the best punishment delivering spells when they get the opportunity. Just as it is disingenious to argue that a thief isn't most often using his thieving abilities to arrange things so that the thief and the party can kill something. Note, I say 'most often', not 'always' ... so don't waste time giving me solitary examples where this isn't so. I know it isn't always so. But a thief using thieving abilities isn't worthy of an X.P. bonus ... do you give a monk X.P. bonuses for dodging missile weapons?
Carl, take note - since the very beginning of my online campaign, I have starved the players of ready cash - not by purposefully doing so, but by accepting that they would rather avoid conflict whenever possible. I do use the g.p. rule in my campaigns, but in total, in 4 months of playing, I've awarded almost nothing this way. I'm quite able to be liberal in my treasure, but I keep finding that whenever I set up a circumstance where the players might do a. and b. and thus get a big reward, the players sidestep and miss it entirely.
I don't find it problematic ... I can play the game forever no matter what the party chooses to do, and keep the tension going. I do find it interesting that I don't need to do anything to keep money out of the players hands - given that money clearly isn't their motivation.
At the same time, I won't reward them X.P. for choosing another path. I hear arguments like "gut-feeling of how hard the challenges ..." and I quail ... it's a sandbox game. If a party wants to make it hard for themselves by behaving honestly, denying themselves fast money, or taking paths which provide little combat or treasure rewards, that is their bailiwick. I don't care what my gut tells me about what they deserve, because my gut has no business as the DM of this game. I am often astounded at the party's cleverness. But it isn't my JOB to patronize the party ... it is my job to provide a system of blind justice.