The only reason I liked capped level content was because I felt like my character was growing with the story. But my experience is pretty different than most people's, I was fortunate enough to pretty much level as I progressed through the story, and I had a static/friends helping me so I never felt that pane of waiting for a group to do it with.

I'd have to say...I'm against it if it's anything like FFXI where once people progressed they generally had no interest in returning. However if they offered rewards for returning to assist players going through the content, I'd be all for capped level content. Can be anything from synthesis materials for higher level crafts to maybe special pieces of gear or maybe even some aesthetic things for your character(for instance after clearing content a certain number of times can get a unique hairstyle or something) Hell, make it so that every time someone earns their first win in a pt, the group assisting said individual gets rewarded 100k.