1. They modify certain non-essential NPCs in Morrowind to be werewolves. They aren't everywhere but not too far off the beaten path. There are a grand total of 16 new werewolf NPCs.
2. They allow you to become a werewolf outside of the Bloodmoon main quest, WITHOUT breaking it.
3. Once you beat the Bloodmoon main quest (were-betterer stops transformations for all but the middle of the bloodmoon main quest) you only have to transform into a werewolf at the full moon.
4. Being a werewolf now gives you a stat bonus to your non-were form. Beware, you will lose it if you choose to cure your lycanthropy.
5. One of the Bloodmoon werewolf quests will give you a slightly better reward.
6. One werewolf NPC will recognize you as a werewolf and say a few words about what it's like to be a werewolf. No quests are involved as of yet.
7. Basically makes it a bit better to be (and stay) a werewolf
IMPORTANT INFORMATION about Moon phases!
Remember that full moons in Morrowind are a bit annoying to deal with. The phase changes at midnight and it ONLY changes if you're in an exterior cell. If you happen to be in an interior cell at midnight then the moon phase won't change. Night runs from 9pm to 6am.
If the moonphase is already full then you will change at 9pm. But on the first night of the full moon the moon phase will change at midnight and you will instantaneously transform into a werewolf. So you should stay away from NPCs around 11pm and 8pm
Thus far the only way to tell the moon phase is to either watch the sky or type into the console: Getmasserphase or Getsecundaphase.
The two moons ALWAYS have the same phase so it doesn't matter which one you type.
(The dwemer clock mod does NOT appear to function properly for this mod)
If you choose the console route, you will get a number from 0 to 4 as your output
0 = New Moon
1 = Crescent
2 = Half
3 = Gibbous
4 = Full
Unfortunately you can't tell just by the number whether the moon phase is waxing (going toward full) or waning (going away from full). The only way you can tell is by watching the sky and/or seeing the number increase or decrease by using the console.