I mean, some useful ones like azhidal are considered heavy, which throws out the mage armor perk for alteration.

I never use them personally because I would rather see my mage characters' faces.

I'm with you on that.

I use Miraak on my mage.

the one before u fight alduin and the one u get during the mage college line are pretty good

Some like Morokei and Nahkrin are I believe but those are light armor so I believe they still Void mage armor.

The random effects from Konahrik sure make for fun gaming.

You've bitten off more than you can chew, the baddies are dropping your health 20/25% a hit, you try to retreat but there's an obstacle behind you so now you're stuck, your health is down to a sliver and you're about to hit the potions when ... everyone bursts into flames around you, or a dragon priest atronach pops up; all while you heal. Good stuff.

I found Morokei to be pretty useful.

I don't like them. They're hideous, and interfere with my lovely mage armor. Plus only a few actually give magical benefits.

As a player i've always been a bit more aesthetics > purpose, so if masks look good on my character and fit reasonably well (or even loosely) for his playstyle ill take it. If they butt ugly, like the brown one (forgot its name) I would just leave it at home.