I agree with Honda and Steve, no two mods are exactly alike, and when you switch brands the difference can be even more dramatic. I started on a Kanger Top Box Mini, it was good. Went to a Kanger K Box 200, and what a difference, a little stouter hit, better flavor, lower wattage and better battery life. Changed out tanks to an Aspire Cleito and WOW!, huge flavor boost. Now I'm running a Geekvape Aegis with the Cleito, and it is totally different than the K Box. Hits harder, better flavor still, etc. You would think going from a 200w to a 100w mod would be a downgrade, but not in this case. There are so many things that can make a difference. Tank, batteries, the chip programming the manufacturer uses, coils, and the list goes on. For your shortness of breath I'd say maybe dropping nic percentage might help. I'd also say drop the hit to soft or low or whatever Smok calls it, and drop the wattage then experiment up and down till you find your sweet spot like Steve mentioned. Good luck, and have fun.