You were asking about ohms - that's a whole other beast. Here's the thing. You're getting a twist, a device that let's you go from 3.2 to 4.8V. The great thing with that is that you can use any of the replaceable heads that come with the stardusts, nova and T2s and simply adjust the twist to where the flavor, vapor and throat is just right for you. They usually have 1.8. 2.4 and 2.8 options and I think GotVapes has a new head that is 3.2 ohms (a bit high, I think, for a twist that only goes up to 4.8V). Get one of each type for any device you choose to buy and twist until you find the combination you like the best and stick with that.
Now, if you care to dig deeper, here goes. As you probably know, watts determines the amount of heat being generated for a given combination of resistance (ohms) and voltage. The formula: (V x V)/R. Where most people like to vape is in the 6 to 8 watt range. Some like it really hot and prefer to go all the way up to 12 watts! Not me, but to each his own. Where you land in the spectrum you'll find out soon enough. Personally, I like 7 to 8 watts. So...
A 1.7 ohm (low resistance) atty I'll set anywhere between 3.7 to 3.9 volts
A 2.4-2.6 ohm (standard resistance) atty ill set anywhere between 4.2 and 4.6 volts
A 2.8 atty maybe at 4.7 or maxed out on the twist
Anything higher than that and I'm using my Provari in the 5+ volt area
Why the wiggle room in volts for a given resistance (why don't I always set my 1.7 at 3.7 volts)? It depends on my mood (if I want a nice kick first thing in the morning, then I'll go higher; at night maybe lower to relax and chain vape). It depends on my device (a little higher on a dripping atty that can keep up with my chain vaping, a little lower on a clearo where I don't want to risk burning out my wick/coil prematurely). It depends on my juice (certain flavors taste great when vaped a bit hotter, while others are better on the cool side). Another thing, and this seems logical, but you tend to get more vapor when setting the voltage a bit on the high side for a given resistance and if seeing plumes of vapor is your thing then you'll likely end up vaping at higher voltages.
So. Most important thing is to get a variety of resistances and just see what you personally like. The above are my personal preferences and general guidelines, but your taste buds and other criteria for what is/isn't a good vape will be the best way to know. The twist is great for you because you really shouldn't care about the numbers at this point and you can just twist up and down until it just tastes good. Once you found that good vape, look at where you land and make not of it. Do the math and then get a sense of what your preferred wattage is and experiment adjusting the volts on your other attys to see if you get the same vape off of them.
Lastly, some things to keep in mind with the twist. It goes up to 4.8V. Anything above a 2.8 might produce too little vapor and be cooler than you might like. I'd stick with 2.8 ohms on the high end for a twist. Joye, the maker of the ego, recommends avoiding low resistance atomizers for their devices. They're optimized for standard resistance attys as lower resistance is felt to add extra strain on that style of battery causing the battery life to diminish quicker (not just between charges, but in general). I personally use LR attys on a twist all the time,but just something to bear in mind. Avoid dual coil cartomizers on twist (the egos will regulate the voltage to 3.7, no matter what you set the twist to). I don't think you plan on using dual coil cartos/tanks, but there you go.
Have fun and sorry for the wall of info.
PS: if anyone has a link to that famous Safe Vaping Power Chart, please post it here for Edana and others on this thread who may be curious. can't ever seem to find it when I need it!