Hey Brad and Aloft, welcome to CPF and why dontcha stay awhile!
I love my X5Ts, though they certainly aren't my EDC or most used lights. The regular X5T, which Chris now sells for about $30, and the UV (about $40, and I paid more for each of them) are tough, aesthetically pleasing and functional.
The UV, in my opinion, fluoresces things well (credit cards, money, vaseline glass) but puts out too much blue light, so as to obscure some detail. The Countycomm keychain UV puts out more blue light, and gives much less detail. THe guy in Hong Kong that sells on Ebay, has a better UV, and cheaper, at least it was when I got my X5T-UV.
As to the regular X5T, you don't worry about breaking it, it's great to use to around the house, sucking out the old 123 cells, as well as in the glove compartment.
I would not consider the two interchangeable at all. You might want a blue X5T, which is likely brighter than the white LEDs, but you sacrifice some color rendition and depth, so I like white LEDs better. The UV has its niche, hunting scorpions (never done that) and checking the toilet bowl (have done that, luckily not much to see), but is not good for general use, particularly since people like to look into the ends of flashlights, and UV ain't good fer yer eyes.
So, get both (an oft heard mantra around here), but be aware that there are a lot of brighter and smaller torches to be had.
welcome again,
daloosh