First off, I would like to point out that in making this, I'm not saying Destruction magic svcks or is underpowered. I want to say that I have been very disappointed with destruction magic overall.
You start off with your base, novice casting spells, high efficiency, low damage.
You start leveling up and you start getting into apprentice spells with more damage, lower efficiency per DP and much higher cost overall, have dual casting knockback, more effects.
Then you go to apprentice spells, they look good, have even higher damage with EVEN LESS efficiency per DP and much higher cost overall.
Then you go to adept spells, same story as apprentice, but with the ability to damage more than one enemy at a time.
Next is the expert level, which is the same story, more damage, more cost, less efficiency but they EVEN got rid of the splash damage. Worthless.
Finally to top it off, you work and work for level 100 destruction you expect a BEAST spell that at least will be able to replace the Adept level spells you have defaulted on because they are at least decent.
What you ACTUALLY get is a useless piece of garbage that is in no way shape or form practical OR useful.
You sit for 5 seconds waiting for the spell to charge as it takes MOST of your mana. There efficiency of these spells are ABSOLUTE garbage and the damage is not impressive at all. In the case of Fire Storm, it will HURT your companions and Atronachs, and cannot be cancelled once charged. Others it takes a ton of mana, and lets enemies get close to your person with light armor so you can get killed while casting. The mastery/expert level spells are supposed to reward players for getting that high and are supposed to be the big finale for the destruction tier. What we get, in fact, is a useless pile of garbage that is useful in no way shape or form.

EDIT: Pretty much the only one actually somewhat useful in master destruction is Lightning Storm. Forgot to include that earlier

But it does svck and is underpowered. Make damage scale with level, why this isn't in there defies explaination.

It's not as easy to use effectively in my opinion and you do have to do more work to actually use it effectively.
But yeah why the HELL damage AND efficiency does not get better as you level up and get new spells is just beyond me.

It's already well known, the apprentice spells however are higher efficiency on a single target the the novice spells, just to point this out. By the base damage to cost percentage, flames has a 61% efficiency whereas firebolt has a 69% effciency... Incinerate on the other hand I believe is in the low 30s on base efficiency... and Firestorm is in the 20s... their magicka cost to damage ratios are horrifically bad.

When you can deal more damage with a sword, when having no perks in one handed, than when using a fully perked adept level destruction spell, there's an issue.

The rest doesn't matter.

Spells should scale with level, or they should add spellcrafting back IMO. But i didn't find master spells disappointing, i'm enjoying lighting storm very much.

They should simply make spell damage scale according to skill level like weapons do. Something like for every 1 point you gain in destruction you get a 1% increase in damage so that by the time you've maxed out destruction your spells will do double damage. That way in the earlier levels you get a slight boost but nothing extremely overpowered. Rune spells should also benefit from the increased damage perks or the rune mastery perk should double the damage.

Seems like something people could mod pretty easy. Right? I am having quite a bit of fun with Fireball right now. Incinerate costs to much to cast... but there are times when I can pull out a sword and start smacking things for more damage than I could with my spells. I have been arrow one shotted a few times. I got one shotted on some ice spell... over 200 hit points in one spell?! WTF.

Expert level spells are fine. Master are sad though.

My biggest problem with destruction though is that mana doesn't regenerate while casting spells.

as you level, your magica increases, your perks reduce costs too, so you get more bangs per buck

Hose the place down with Fireballs and send the Dremora in to gut whats left

Well im glad its mages who are nerfed this time around
Melee characters were nerfed in every other ES game

Whine whine whine, you just need to know how to use it.

The blizzard AND the fire master spell are worthless when you have tons of far better spells, there is NO arguing against that.