Good question. The e-pipe did require some adjustment. With my regular pipes (down to about 3 a day now), I hold the smoke in my mouth without inhaling it into my lungs. I thought I'd do the same with the e-pipe. But nothing happened when I used medium strength cartridges that way. So I ordered extra high nicotine liquid and put that in new cores. Still nothing by just holding it in the mouth. So I gulp it down now, a bit different than an e-cig or my e-cigar, but inhaling it. It's so strong it sometimes irritates the back of my throat -- cough, cough.
And I DID overdose badly the other night while using an extremely potent snus and the e-pipe at the same time. Not pleasant for me at all. I learned my absolute upper limit tolerance for nicotine. The snus was about 6 times a normal cigarette and I was inhaling 24mg nicotine from the e-pipe. I think I did about a pack of cigs in a half hour!