I personally like the approach taken for DRK defensive abilities, where you are layering together different abilities depending on the situation. To me it feels more strategic and I like that. I understand that it may not feel as efficient as some of the abilities on other tank jobs and that some people may not like that, but the flexibility gained by having them broken up like they are is worth it in my opinion.
I think the main issue with Oblation not feeling very good is that it is not quite strong enough as an ability and the 60s recast, even with having 2 charges, isn't frequent enough to really sell the feel of it being that extra bit of defense that you can choose when and where to layer in.
While I would prefer a more complex and game-play focused rework of the ability, like the ones that I have suggested in past posts, I think that at minimum they should reduce the recast to 30s if they want to keep it at 10% mitigation, or have the recast be 45s and the mitigation 15%.