In my opinion... (Purely an opinion of me, but it may be shared by others.)
Just for the record, I smoke 18-24, Marb-Ultra-Light, non-menthol.
Well, you won't be smoking like a "Normal Cig"... It is just different.
If you are there for five minutes, vape-ing... you will have a $40.00 habit turn into a $400.00 habit. It is just different. You need less puffing, and more time. You can't have both, puffing and time being equal to a real cig, unless you have one of the giant cigar-tubes and a long extension cord.
Seriously though, the DSE 901 or any pen-style will give you the puffs you desire, but not the size you want.
For the size you want, you will not get the puffs you desire. You will spend more time refilling and charging.
Until they have some monumental battery upgrade, and a more efficient vape-element, you should go for the slightly larger version.
Think of it this way. This is NOT a cigarette. Don't try to force it to be one. You will be more welcome when you are seen doing something that is not-smoking with a device that does not look like a smoke device.
Even if you had a perfect imitation, you would be asked to stop vape-ing, in public, if it disturbed the peace. (It disturbs the peace when it looks like you are smoking in a non-smoking area, and a business owner has to tell everyone that you are not smoking... They will still ask you to stop causing a scene.)
Getting something a little more unique, such as the slightly longer and unnatural colored body and blue-led or green-led device, will appease most people. It actually leads to a more friendly welcome of curiosity, without raising a disturbing situation of wrongful assumption.
You will not be dissapointed with a 901 or pen-style. It is a great entrance.
Also... don't expect it to taste like a cigarette. Cigarettes taste nasty, as you will see, once you get your taste back. (Just like you can't smell your own $#!+ when you have been on the toilet for half an hour... You don't realize how bad your cig tastes when you smoke... and if you smoke menthol, you wouldnt know what a cigarette even tastes like. You want anything with mint and pepper. But not mint and pepper!)
FYI, they use junk
tobacco for all menthol cigs. Because you can't taste the stale flavorless
tobacco over the lung-burning menthol. Menthol causes many nose-bleeds and burns holes in smokers lungs, but it tastes minty... but it does not smell minty to others around you. They smell the stale cigarette
tobacco which you can not smell or taste. (Two years working on a tobacco farm, and you would wonder why you even smoke at all!)