I have really enjoyed reaper to date. Has had some great challenges though extending level 30 further down the epics would be far better IMO. More content.
I would also suggest that for melee something needs to be done to allow them to melee in the more extreme skull content. I have no issue being 1 shotted on my caster or ranged, its the price I pay for being unlucky or too slow etc, but melee have to be right there and against raid bosses or red named they can't use CC.
The issue is that most defenses don't scale differently for melee and other types. HP dice are irrelevant in most cases as the HP difference is minimal at end game and PRR etc can't scale that significantly.
I would suggest that there be a scaling for melee based on them having a melee weapon in their main hand and not casting a spell for a period of time (eg equal to skull level or lose the bonus until that time elapses again). The bonus should significantly reduce incoming damage via melee (not ranged or spell) and increase their damage based on how many times they have hit the mob (eg bosses) all scaled by their BAB.
Casters and ranged would see little benefit from it since ranged don't have melee in main hand and casters would be always on timer from spells.
To make shields more relevant it could give bonuses vs ranged in the same way as melee (only if melee weapon equipped or active blocking after a period of time same as melee).
As for reaper xp I am glad they set it low to begin with and can scale it later (would like level 30's with capped eds etc to get a bonus) and the argument of "its for challenge only" is pretty irrelevant as most would have been happy with challenge only option but once another area is presented to improve a character its natural for people who have worked hard to be at the top to want to max it out.