This guide should shed some light on the followers in Diablo 3 and explain some things you may not know about them that should increase your knowledge about choosing the right one for you.
All Follower Skills do not use resources (such as mana, energy, etc..). The Follower skills only use cooldowns. Thus, equipping followers with +resource has no effect.
Each of the three followers has a special attribute for
increasing their damage output:
You should also know this:
Is there an advantage to NOT using a follower?
The real advantages of followers are the crowd control/healing abilities as well as dumping all your gold finding/magic finding items on them. Meaning you'll be fine without them, but I don't think you'll get any bonuses for not using them.
Although sometimes you may have to dismiss your follower while fighting mobs with Vampiric or Plague, as the mob will get healed constantly with the follower in the way.
Do follower items affect my player in any way?
Such as +magic find, +XP, etc? The answer is: Yes, 20% of the effects are transferred to you. So let's say you give a ring to a follower that has +15% magic find. So 20% of 15 equals 3%. That means you will have an additional 3% magic find.
Can I name my Follower?
No, followers have their own names and they cannot be changed. At least on the current patch. But if you know Blizzard, they change things from time to time, so they may implement name changes for followers in the future.
Is there any downside to using a follower? Such as, will you get less experience? Or less gold? Or less magical items?
No, obtaining experience is the same with or without a follower, same with everything else. There is only benefits to using followers.
Can I switch between followers, and can I keep my current one if I want to switch to another one?
Yep, you talk to one of the followers not following you in town, they will have a 'hire' option. And when you hire another one your old one will remain with you for ever. They will be in town and to use them you simply click the "hire" button on them according to which one you want to use.
Did you know that followers do only 15% damage to monsters? But why?
The stated goal of followers by Blizzard is support roles. They heal, crowd control, buff allies, debuff foes. They don't want you to rely on them for damage.
Damage was nerfed so that they would feel truly optional. I think they succeeded. I do agree that the offensive abilities are going to generally suck however, unless they bypass the 15% damage dealt nerf.
Are followers useful after normal difficulty?
In early development they designed followers to not be viable past normal. They were originally designed to just be apart of the story and that was it. After alot of negative feedback about how the community didn't like that concept - They reverted that original idea and made followers viable in even inferno difficulty.
For more info on followers, I highly recommend checking out Diablo 3 Gold Secrets By Peng Joon, there's a small fee for it, but well worth it.