The markup in the templates is meh, the stylevars system is a mess, hard coded css file including within of multiple templates, etc. I'm working in this system for a friend, and my god is it a nightmare! I'd much rather use Invision Power Board 3's style system, even though I don't like that as well and used to be a vBulletin fan...
From the combination of the style/design decisions that come from the staff and the worries I have had since hearing the development of vB4, I've rest my case in never wishing to work with vBulletin software again. Granted I must for this project, but my love for vBulletin died when 3.x series did. Sure, the series had questionable markup and didn't have the whole "separation of markup & design" philosophy nor proper use of markup, but it still have the design conventions that are alive today, with a system that could actually work properly.
As it stands, the Stylevars system is a good concept with a very horrible implementation, and here's why:
The stylevars is laid out without much indication on what variable modifies what.
Far too many style variable sections, which a lot of them could be combined into one editor page. (for example, forumhead_x series of vars could be one editor page)
The user interface breaks the design flow of the other admin pages, and is a unnecessary hassle.
No ability to add additional css per style variable set or individual vars.
"forumhead_top_corner_radius"!? Really? border-radius isn't even standard, let alone being a randomly added asset to support vB4's default theme.
And I'm sure there's more I didn't bother thinking of at this time.
You went the right way in the concept of such a system, but you did a horrible job in actually creating and implementing it. The templates aren't much better, I mean the section for many templates is not just limited to header_include (which makes sense for things like exclusive javascript) but really... You force CSS styles in there!? That should stay in the header_include! Now I can't even scrap your style system without more and more work.
I must say, vB4 is only a plus for the average user, with a bit going towards advance (at least in a technology aspect). Otherwise, the software is a spit in the face for true UI and style enthusiasts. I will have to continue my work, even if it means using stylevar replacement manager to break the forced CSS being included in the templates so that I can link my own style sheet.
I know this is a harsh message, and sorry for being overworked on such a tone. However, I'm sure you can at least understand the frustration I have when I used to hold up the vB name with honor.
__DEFINE_LIKE_SHARE__