Dangerous enchantments don't have a downside or a trade off with anything because they don't cost enchantment points. You aren't losing a mod slot in order to have dangerous enchantments on them. You can have a max enchanted weapon WITH an additional mod on it with transmutation AND 300 damage from the dangerous enchantment. That's why there's no choice or customization. When level 80 weapons come out, it will be the same deal where there is no reason not to want +300 damage on it aside from not wanting to go through with the frustration involved with gambling.
This is not true. Simple damage still gets multiplied by a few bonuses. In fact, it gets multiplied by any bonuses that would also multiply base damage bonuses. The only way +300 damage would be worse than 20% base damage is if the base damage of every attack you use is greater than 1500. The highest base damage out of the three current weapons is Decapitate at 761.

