A play experience where you stay together and work as a group is what I am hoping to find.
I'm more interested in the journey than the destination. I already have a few characters at cap but none that have experienced challenging content working as a team across all levels.
I would go with whatever the group wanted, designing a character build that complemented the overall team strategy and fulfilled whatever role was most needed
Reaper is already generally available to my fleshy characters. I feel confident soloing 2 skull with a hireling for most of my characters; opening up the lfm, and then increasing difficulty as other party members join the group. I've been in pugs at 6 skull difficulty on heroic 3bc but that was the exception.
My undead characters are built for self healing. I don't see them generally being viable at higher difficulty settings unless they were supported by other characters who could also heal undead.
One of the things that makes DDO fun is the diversity of build options. For me, it will be more fun to play the type of character (undead, warforged) that I can't otherwise already play on my own in higher difficulty Reaper