Elio is a high risk high reward class with probably the best revive (if utilized intelligently) in the game. Not to mention portal play and it's role in support trumps rails in effectiveness which means they drastically change the shape of the map in the allies favor.
I never have problems with Incandescence simply because chaining it makes that damage effective damage all the time regardless if your teammate kills the target you've placed it on.
Unleashed Blade may see more use simply because AI tends to end on portals more so now then previously (what I've noticed, not verified). But it's still a nice damage option if your more CC oriented.
Xelor and Elio are two completely different support roles. Xelor focuses more on buffing allies ability to do damage and has a secondary movement function where as Elio's are the reverse of that statement.
Exhaltation is your DPS button, point blank, period. If you don't have a means to using it effectively, you shouldn't, flat out. That's why distance Elio is viable so you can safely attack from far away if your not tanky enough to be exhalted in the fray of battle...