I like Groupmanager better that and the commands are shorter and more simple
Pex -> /pex user <user> group add <group>
GroupManager -> /manuadd <User> <Group>

Pex is it wayyy more flexible.

PermissionsEx.

More customizable if you take time to learn about it.

I don't know how to feel about Groupmanager. I think people are perfectly entitled to like Groupmanager more for some reason, and that it's stable and useful to some people, but I've been using PEX since I've been running my server and it's just what I know. I worked on a server that ran GM some time ago and I found the commands to be a bit eldritch. "Manuaddp"? what? I mean, it makes sense to use but I find it harder to remember all of the GM commands than typing words that make sense, in a sensible order, like "/pex group default add perm.node" etc.

Groupmanager.
Quicker and easier to use

Group manager

Please could you guys help me setting up PEX then?!?

Pex

PEX is way better, you just need to get used to it and isn't that long. If you have a multiworld server, don't even hesitate: PEX! Contrary to what people said above, PEX is compatible with every single plugin and doesn't have any bug while GroupManager is not compatible with several plugins.

group manager all the way i tried pex didn't like it, just make sure to make use of mirroring users because it can be real annoying having to add a user to per group per world.

PEX is a lot better with compability like buycraft or donationcraft or vote listners etc. Its pretty much the same otherwise exept for the fact that most people are too retarded to be able to properly use it.

Ok good job is the server hamachi? If not do you need help?

Im using pex i can switch anytime but i think i like pex

I've tried both they are pretty much the same but pex you can't promote them real time or it's just I don't know how to but that's why I use group manager pex is used on big servers tho like opticcraft.tv and woodycraft.net but it should be your matter of opinion

I really prefer PermissionsEx. I think it is very stable and It has worked for me for about 3 years. I can see where people are coming from when they say it is hard to use etc.. But if you learn how to use it properly, you can figure the rest out yourself (if you have some kind of knowledge).
In the new update, Chat manager was not going to be supported anymore, HOWEVER! a new more simple chat plugin (which hooks directly into a few different permissions) called ChatEx is a very lightweight plugin that I didn't have to even configure when I installed it. Personally I prefer PermissionsEx because it is much easier to use and you can have a lot more fun with it
My Opinion.

~Womble out!

I say GroupManager. It is easier to setup. I tried PermissionsEx and it is so hard to setuop

I personally use PEX, It works. Many of the 'bugs' they speak of were removed a very long time ago. It's really simple with multiworld and, I can't stand the way Group manager does it with more than one perms file. However, with the update for pex, I will be probably changing.

Dino since your a friend I use group manager I can give you my old perms if you want

People only use it because it has been deemed as "most popular".

Groupmanager has been my friend for 3 years on my server.

PEX is full of issues that "Coders can use to gain access"

GroupManager since it uses the good ol' super perms system. PEX is a nightmare for developers.