Yes I don't own a 2100, I think I just made a mistake of buying the X1 but will see. Will be getting myself a 2100 once I have enough funds.
The only bad thing about the 2100 is the noise. It whines worse than my kids! It even makes a clicking sound on strobe.
I was talking about this eastward but it seems they are sold out of it and ...sent DR Jones a different model ..ah the joy of DX ..anyway i thought it looked sort of nice
The Uf 2100 looks good when "baked". It turns a very dark brown.
Everything looks good when your baked.
My 2100 was silent untill once I accidentally dropped it, then it started making that loud noise which would go away if I pushed the tailcap hard!
I took the light apart then put it back together and since then it's silent as the grave.
Wow! That must be crazy thin! It’s no wonder you only drive it at 1A. I’d rather have an extra MM or two and a more solid light.
UF-2100 is available for $15.99 now at DD. Bring it down further with coupons and dd points.
It is 3 mode but you can mod it to 5 modes if you know how to solder.
I cannot hear the hum of my UF-2100 unless I place it very close to my ear. It's soft. The hum could be due to the high pwm.
Just saw this light in cnqualitygoods
Anyone have this?
Citycat YEE-Lic
113mm*23mm
http://www.cnqualitygoods.com/goods.php?id=1527
Nice find... with neutral and warm option.... very nice indeed.
Wow! Those Citycat lights are nice! If Ric could do a GB at $25 shipped he’d blow out a ton of those. I’d snag a grey/blue in neutral in a heart beat!
I'd be interested in a GB, love the grey-blue. Price for 10+ is $23
I likee .
That is a price with no shipping included and all going to the same place. He won’t be able to do that price shipped individually to everyone. Usually when he does a group buy he uses the middle price and includes shipping. It allows him to still make a profit while saving us a few dollars. More than fair in my estimation. Every time I look at those pics I can’t get over what a clean, sharp design that light is! 
After ordering the Citycat YEE-Lic in grey/blue + neutral (will this weakness never end?!?), I saw some other new slim 18650 lights on cnqualitygoods:
"FUBROTHER T6-28" (what a name...) with XM-L - only on CW though:
http://www.cnqualitygoods.com/goods.php?id=1486
Eagle Eye Super bright Mini - wow: "Thick copper circuit warehouse" 
with XM-L: http://www.cnqualitygoods.com/goods.php?id=1524
with XP-G: http://www.cnqualitygoods.com/goods.php?id=1525
Also this thread might be helpful:
https://budgetlightforum.com/t/-/5773
Just more proof that the longer you wait the nicer the lights get ... think I'll wait a year or two ....
wake me in 2014.
I'll need a light to get to the bathroom really badly by then :P
JohnnyMac:
$23, $25, whatever it takes, I'd be in.
@surprise:
Just can't past the name (FUBROTHER) on that light - I keep thinking FurBurger or F.U. Brother. The Eagle Eye you linked to is a nice looking light, but I don't see any dimensions - I'd like to see how it compares to the size fo the S-mini.
I was looking at the CityCat website a couple days ago but they only show images for the Yee-Fi model. I was really curious what else they have in the compact form factor. I have to say this is a pretty decent looking flashlight for what it is. It's also HAIII so hopefully that translates into quality with the rest of the light.
I like how the first two models he carried (Yee-Fi and another) came out as CITCAT on his website and they're still listed with that name. So now we have CITCAT and Citycat, which are all Citycat.
More pics: http://item.taobao.com/item.htm?id=14033322891&spm=2014.12037222.0.0
Thanks for the link to Taobao, weiser, found the dimensions: 23mm x 115mm. Just a hair bigger than the S-mini (22mm x 114mm).