I think the first (maybe second) dragon priest I killed had the awesome mask of archery and... I think alchemy? IE, the absolute best headgear in the game for my character without custom enchantment.
I loved that mask so much that I went out of my way to hunt down the others, even though I would never actually use them
Also, I found it a lot easier to hit dragons with arrows than with spells. And my arrows, coated in intense poison and fired from stealth, actually damaged said dragons... Seriously, I tried making a destruction mage 2nd playthrough, it was pure masochism compared to archery or even casual melee. Particularly after my most powerful Oblivion character was a mage, of course... They just nerfed magic so hard. Maybe the Nords are like Orks and their opinion of magic weakened it
I think maybe part of my problem is that dragon priests, being undead, are immune (or very highly resistant?) to poison. I didn't try stunlocking them... Maybe part of my problem was focusing on fire for extra damage, when I should have been using ice to stun or electricity to mana-drain-
Except I thought undead were immune to cold?? Liches are immune to lightning, or at least they were in Oblivion, and I assume dragon priests are too (maybe not).
I kinda discounted cold spells since... well... it's Skyrim
Nords and undead and ice creatures everywhere. And the shock spells were so hard to aim... I kept the Altmer companion around to cast, but I didn't expect him to do much damage (and I wasn't disappointed). It was more because he was cute, and it was easier to keep track of him when he kept throwing fireworks like a pixie. I liked to imagine that the Nord bandits always targeted him first for being an Altmer and a mage, hehe.
Speaking of Nords, I sure got sick of Nord companions shouting "Skyrim is for the Nords!" as we struck down Stormcloaks. Me being a Bosmer, Khajiit, or hell even a Breton! Cut it out, assholes!
Though the worst was when I was a Khajiit and we had to fight another Khajiit. That companion made a fine rug, oh yes indeed. Haha... no seriously I murdered him.