Changes the vampirism bonuses and penalties into the oblivion version. It does not affect the Vampire Lord form.
Fire weakness is reduced to 20 30 40 50% from 25 50 75 100%.
Frost resistance removed.
Sneak and illusion bonus removed.
Sun damage added. 0 1 4 8 damage/sec. while on daylight. No sun damage in the first stage.
Health Stamina and Magicka penalties, and regeneration penalties removed.
Stat bonuses added: 10 20 30 40 to all stats
Skill bonuses added: 5 10 15 20 to all skills
Damage resistance added: 5 10 15 20%
Couldn't add paralysis resistance, but enemies rarely use paralysis effect against the player.

Compatibility problems: stuff that change the base vampirism.
Bugs:
If used on a save where you are already a vampire, then you must feed before it takes effect, and you must remove the original 2 buff from the spell list.
player.removespell f5b54
player.removespell 10f1e7

The skill increases doesn't show on the perk panels for all skills, but still takes effect, and can be seen on the active effects panel.