The Zmax is definitely not the size of an eGo. It uses 18650's which are the longest size batts there are, and close to the widest. I know it's a bit slimmer than a Provari, but i've never held one so I don't know exactly how much, but i'm sure they're at least 20mm wide, where as an eGo is 14mm wide. That may not sound like much but the difference is quite a lot when you compare the two. He may get used to it though. I remember 2 and a half years ago thinking my 510 was bulky compared to a cig, then I got my eGo and thought it was really big! Ha! Now i'm using a GGTS and a Penelope, and the GGTS is 23mm wide but I absolutely LOVE it! People's vaping preferences greatly evolve as time goes on, which i'm sure you know. I assume he hasn't vaped nearly as long as you have?
Sorry, I missed the mini part, yes it will definitely be a lot shorter, but it will still be wide! People always talk about liking 18350 mods for on the go because they're so small, but to me width is definitely more important. I would prefer a 1000mAh eGo Twist (freaking long!) in my pocket over even an 18350 Wizards Apprentice (as far as I know, the smallest 18350 there is) because the width is what is felt in the pocket, not the length! (all talking about myself, keep in mind!) Though I definitely prefer the feel of a wider mod in hand (the GGTS fits my hand perfectly!), I do NOT like it in my pocket as much. I brought my TS to work yesterday and man did it feel bulky. I could feel it there the entire time.