My 2 cents worth (based on my usage of my own x cube 2 and my friend's snow wolf)
If you wanna build dual coils etc, try to get a mod that can go over 80w.
Snow wolf v1.5
(from what I gather from their site, v2 won't be out till feb)
1) pulsing. Anything after 150w it'll pulse, so it's not true 200w. (Read it online)
2) not upgradable. (So totally no support for better TC or newer coils)
3) not sure if you can support SS on TC Mode.
Smok X cube 2
1) TC not very reliable (many problems reported online)
2) upgradable (used to be 160w now it's 180w with better TC, reportedly)
3) firing button may be a problem in the future (spoils easily I guess)
4) support Ni, Ti And SS
5) bright and colorful firing bar (but can be switched off)
But nevertheless, I still went with the x cube 2 over the snow wolf. In hopes that they will push out more updates that fixes the TC. As for the firing button, I'll gamble with it. It it kaputs, it's a chance for me to dismantle it and try to fix it.
And lastly, I'm just itching to try SS on the TC Mode. And it can set the resistance coefficient.