Have you tried it yet?
If yes what do you think of it?
Personally I'm waiting for the next minor release before I upgrade mine.

I am installing it right now. I'm having a problem with the credit card module though. It seems to send back decline credit cards when we try to run credit cards through. I hope its just me and not something WHMCS wide.

I think i'm gunna wait for another version of it to come out...This way I know it is a little more stable.

Hmm, there is some interesting new features

Probably a good call.

Yep, wouldn't want nothing bad to happen

I've tried to download it now from my client area, but I getting error
"Access Denied - You must be logged in to download this file"

Does anyone else getting same message when click on download link?

Many great new features, I especially like the addition to the HyperVM module.. I don't really care for the new admin interface, although at least I can change it a bit if I want There seems to be a few minor bugs to be worked out, though I'm not experiencing any of them personally.

I expected it's stable release on the 15th, which was holding up a few of my projects(clients wanted me to use v4 on their new site) so I'm not complaining that it's early.

I have upgraded to V4 - The admin interface will take a little while to get used to it though

We upgraded our WHMCS to V4 too. Everything working fine. There is few really useful things in this new version.

Btw MH-Andy, Admin Interface in V4 working on V4 Skin
That skin was very strange for me too , So I changed it to old on in My Account Settings

Looks like there's some minor issues passing smarty variables within the templates.. Nothing a slight workaround can't fix, but it's not perfect yet.

It is quite nice, A little getting used to, I think there are a few minor bugs but that is ok, It did not screw our template which was good - Overall I would rate it a 7.7/10 ...

It's pretty cool. I like the Multi Currency option added.

i prefer continue with 3.8.2 and wait for 4.01/ 4.02 version update, too many minor bugs for now.

The new v4 is very interesting and has a lot of improved features. That being said I would wait also before switching over to this new version, it just came out and switching over would be from my point of view risky ....