Rated 5 out of 5 stars

Here are the screens to show the difference in the tab loading:
http://dl.dropbox.com/u/37057/loading-old.jpg
http://dl.dropbox.com/u/37057/loading-new.jpg
As you can see the loading icon on the left is different and the progress bar does not go through the middle of the tab.

Also the options pages have quite a different colour scheme from before:
http://dl.dropbox.com/u/37057/options-old.jpg
http://dl.dropbox.com/u/37057/options-new.jpg

And also the menus:
http://dl.dropbox.com/u/37057/menu-old.jpg
http://dl.dropbox.com/u/37057/menu-new.jpg

This review is for a previous version of the add-on (1.1.1).  This user has other reviews of this add-on.

difference in the tab loading
Are you using some special addon like fission? Try v1.1.2 I changed something on tabs, maybe this is fixed for you.

"options pages have quite a different colour scheme"
Thats right, I used some code from Nuvola. Maybe I look at it someday but is this really a big problem? Noia 4 is not a Noia eXtreme clone for FF4 so it may have some different settings. ;-)

"And also the menus"
Thats strange. That bug was fixed before I released Noia 4. I do not have this bug neither on Win7 nor on XP. Can you provide some more specs from your system and you firefox. Are you using Linux/Mac OS?