There are discussions of cree u2 and u3 modules for quite some times (more than a year). I can barely find any Ultrafire or Trustfire that has one of these modules. Usually ultrafire and trustfire are pretty up to date with the Cree LED lights, but not this time. What’s the reason of it? Why they do not make those anymore? I check their website, they only have until T6, no U2 or U3.
LightMalls has a nice UltraFire C8 w/U2 (Also new model posted of UF C8 w/U3!) - they also have an UltraFire V3 (UF-V3) w/U2 though this light is under driven but nice. Of course I-O has the XinTD C8 with a U2 or U3 option for $30/$32 - probably best C8 around. I also have a UniqueFire F12-A w/U2, but kind of a specialized light - mod'ed with a driver, change out the tail cap, bend the clip and it's a decent pocket light - pricey but lots of Stainless Steel which I like.
Dunno why the U2 hasn't caught on more, but recently I've seen price drops for the U2 and U3 LED stars, so I'm sure cost has a lot to do with it. For the xxxFire lights, I'm sure they figure just stating XML is good enough and not worth another 50 cents to $1.50 for saying U2 or U3. Right now, it looks like the U2 is available in 1A and 1B, while the U3 is only available in 1C. On an aluminum star the U3's are going for $7 now, was $8.50.