I do and heres what I think:: 
 
GGTS - Things I like and dislike about this mod 
 
First off I will start with the things I like about it and finish off with what I dislike and any recommendations that I have. 
 
I was originally attracted to the GGTS because of the design of it w/the engraving, fancy button and high shine. 
 
With further research I found that it had vent holes as standard.   This is a must for mods, especially tube mods.  It also has an adjustable draw w/the ability to blow out your atty without removing it from the mod.  This is just pure genius IMO.  I have a tendancy to over drip sometimes and this makes it very easy.  It would be a real pain to have to unscrew everything just to blow out the atty.  Its a pain to unscrew and remove an atty from my other devices as it is.. Also has a locking button and you can unscrew the telescope a bit for safety in transporting. 
 
It is made to accept all attys. It has a 4 in 1 connector to use 501, 306, 901, 801 and 808d type atomizers and cartomizers.  To use the 801 though, you must get an 801 adjustable draw cap. To use a 901 you must screw on one of the two included thread adapters. 
 
Vape quality is excellent.  For some reason my attys perform better on this.  I found a big difference trying out the Ikenvape Mini 801 2.0 
I never liked that atty, it did not taste good on my other mods. I am a LR 1.5 user but then I tried it on this as a lark and found it did vape much better - In fact I like it now. YMMV 
 
Another great feature is that it has telescoping ability to accept an array of different battery configurations, for 3.7v, 6v and 7.4v  For example: 
 
Single Batteries - 14500,14650,CR2,CR123A,16340.17340,17500,17670,18350,18500 and 18650 
 
Double Batteries - 15270,16340,17340,14500,CR123A,CR2 and 18650.   The 18650 and 14500 requires an additonal purchase of an extension sleeve. 
 
I ask you, what other all mechanical mod has this ability?? 
 
 
A tank system is also available to buy if you want to automatically juice feed your atty or cartomizer. VV add on coming in 2011. 
 
Overall: Excellent design and vape quality - a solid 10 out of 10 - I would not hesitate to recommend this to anyone. 
 
 
 
Now for what I dislike: 
 
Nothing - Zero - It's an amazing device 
 
 
My recommendations: 
 
Since this is an advanced user device, it would be greatly beneficial to read the online user manual and watch all the videos available.