No!. It is only good in the short term, once you get the master level spell those 3 perks are totally worthless and have gone to waste. assuming you are leveling to 50ish 3 perks is far to many perks to throw in the garbage. I think it is horrible game design to have the end spell destroy 3 of the perks you have in a fairly small perk tree, but there you have it.
Agreed. Even with the 3 perks, ebonyflesh will only give 36% damage reduction. Pretty pathetic in my opinion. This is why I'm planning on making a mod to up the perks to 2x, 3x, 4x and converting dragonhide to a "flesh" like master spell. If you're on a console, skip the perks and level alteration to 100 as fast as possible to get dragonhide.