Nords, Dark Elves and even Bretons seem to have an easier time of it with their resists. Flame and Frost resists (or even Magic resist) becomes rather essential but also eventually really impacts difficulty. The game is pretty gear-dependent too, unless you're an alchemy whiz or a thief that finds enough potions. What Bethesda does right is allow you to change the difficulty in-game on the fly. As stated, that is what mods are for - if you really want more challenging play that is smarter and not just a damage/health modifier. The thing is that people get tied up with difficulty levels when they are going to vay by player and also do little to make the AI different. But for many, Expert is closer to Normal.
Adept is suppose to be 'Normal' difficulty, (as the name implies) which means for persons experienced with ARPGs.