The old style auto added points based on what attributes you used. So if you leveled destruction a lot during level 5 you could get a boosted willpower or Intelligence stat when you leveled up. It was a little chaotic. Now you have 12 stat points(virtues) you can add to whatever 3 attributes you want maxed at 5 points per attribute.

IIRC in the old oblivion there was an arbitrary limit to how many skill points you can put in a stat depending on your class. This has been removed, you can now put up to 5 points in a single stat every time you level up to customize the build as you'd like. You get the same skill points regardless of skills you leveled up.

Some stats have been balanced, like how Agility now scales damage of daggers and shortswords now (before it was only bows). Many masteries have been rebalanced and changed to fit the playstyle more. Enemy scaling still exists and AFAIK enemies scale the same, but because leveling has been reworked you shouldn't have to worry about min-maxing or what skills you're gaining.

As for face animations, they're a little uncanny but overall I'm impressed with them. They look great, most of the time.

I haven't played the remaster, but the old Oblivion leveling system was exceedingly hard to do efficiently unless you planned in advance. It very much needed a rework, although skyrim dumbed it down way too much, in my opinion.

Basically, among all the skills, like destruction magic, blade, sneak, you pick 7 (I think it's 7) major skills. Those get a boost at the beginning. When you raise your various major skills 10 times, you level up. When you level up, you get to raise three attributes, like strength, speed, or intelligence. You get bonuses to how much you can raise an attribute per level, with 1 being the minimum and 5 being the max. The bonuses are determined by what skills you raised during the last level. For example, the sneak skill is tied to the agility attribute, so raising your sneak skill gets you a bigger agility bonus on leveling up. So, to optimize it, you'd have to raise your major skills exactly 10 times (so none of them go to waste) and fill out the bonuses by raising minor skills, which don't count towards a level up, to get the ideal spread of +5 to 3 attributes per level.

The main problem with it in Oblivion was that the enemies grow stronger as you level up, and since a lot of people didn't understand the leveling system, they'd wind up with horribly underpowered characters in the late game. Some people deliberately remained at level 1 to keep the enemies easy.