There's not much one can say without spoiling anything, and this is probably the most complex and dense hero show one will have to opportunity to watch. Agito is a very story-centric supernatural mystery, one which action and characters generally taking a backseat, though not to a large degree. with that said, this is likely the most epic show of the variety, very reminiscent of Power Rangers: Time Force, but kicked up quite a few levels. The show is also targeted towards adults, especially in comparison to the recent rider franchises.
Action and production values are high, though it isn't as glossy as say Kamen Rider Faiz/555 was, it still avoids being visually dated. If anything, it's a modest show, and that dates it. There is no real flash, and it isn't needed.
If you ever have the opportunity to watch, it should be a pleasant surprise.