In my opinion its just better built, it's a really nice mod..
The older coils were horizontal, the new ones are vertical, they vape better, better flavour and don't flood or dry hit for that matter like the old ones did, I hated the old ones and I stopped using my subtank mini for that reason. These new ones are great, they can take higher wattage too..
Yes there are nickel temp coils available too but you would need a temperature controlled mod to use them, both the Coolfire 4 and the Istick 30w will only fire Kanthal..
New Vertical coils
HERE