I pretty much like it the way it is except for a color change and/or texture change in a couple of places.
Daro - tell me which textures you are wanting to change and I'll see if I have the Photoshop source for that window. Some, like the compass and hotbutton window I redid from scratch so at east have photoshop files of the window cut into pieces and layered. Others I just edited the textures directly (don't forget to check their alpha channel).
My change will be a very simple change and will just have to put a new texture, mostly likely in the chat background windows so I think that just involves one file.
What I attempt to do is to make sure with a very quick glance of the screen which instance of EQ I'm on. In the heat of a battle I find that sometimes I get confused and hit keys trying to get the cleric to cast a healing spell but nothing happens since I'm on the warrior. I solve this by changing the look of the UI. I found that changing color is the easiest method and achieves the results of me quickly spotting what character is active.
For example: If I am playing a Warrior, Enchanter, Cleric. I would set main colors on the screen so Black would be theme for warrior, Blue would be theme for Enchanter and Green would be theme for Cleric. Therefore I know immediately which character is currently active without having to look at the character's name. It keeps me from attempting to cast a heal with the warrior.
I've tried running different UI's but over time I have found that color change is the most effective for me and sometimes you find an UI that just works well and therefore why use others. I've always like my modified SARS3 so that has been my UI but this SARS4 seems better for me so far, so I'm pretty sure I'm replacing my SARS3 with SARS4MAC