I think it works to solve a lot of the current problems. A lot of users in #perlmonks saw room for improvement in the current XP system. I wasn't completely pleased with how XP currently works either and asked them for a proposal to fix
it. This is what they came up with.
Personally, I think it does a good job of addressing the current problems.
As for giving reasons to users for votes given on nodes one issue is user-interface. I don't want to see drop down menus everywhere or additional text boxes. I think the best thing might be to allow mini-notes to be added to a node that could only be viewed by the author. It would also be interesting to gain other stats on users posts such as accuracy, helpfulness etc... and maybe some in the opposite direction as well. I think the best we can do on this sort of feedback is make it optional.
vroom | Tim Vroom | firstname.lastname@example.org