Experience
The daily ticks is actually a timer until you can level up again. While RP experience is a good idea, the combat XP is totally pointless. I would hope that the combat XP would take way longer to gain than the RP XP, but at the moment you can get all the combat XP in one day, no matter the level. So you burn out the little feeling of progression so fast that you are back in the square, doing the square RP again in no time.
While I don't exactly want to chime in into the rest of discussion, I will only say that the combat XP statement above is simply not true for high epic characters. Quite the opposite, especially for casters that are researching the Epic Spells, gaining combat XP is a chore and grindfest, effectively discouraging high-level characters from any activities that may cost XP. Moreso, the anti-taxi system forces those high-epics to band up (And exclude lower-level toons or be forced to grind even more) to get any reasonable amount XP or to solo, which is, from what was said many times before, not the way the epic content is meant to be played.