I lucked into maxing a Maximum UV so here is the compare image vs the non UV version of the same item in case anyone is interested:
http://wiki.spiralknights.com/File:Max_Elemental.png
Doesn't seem to provide that much of a difference to be honest. Though I know it is only a 2* item right now.
You're right. Look at it again when it's 3-4*. Or rather, don't look at the bar, and only pay attention to the actual amount of damage you take when hit. It's much harder to do that, but the bars don't really mean much, as they are incredibly in accurate in comparison to each other, and even the gear in their own lineage.
I used to be interested in this stuff when I thought the visuals gave any clue of UV quantity, but they don't. Thanks though!