on off on off on off on off on off on off .... put it in your pocket
then
on off on off on off on off ... and put it away again.
repeatedly, hour after hour day after day week after week etc..., that's a lot of on off cycles... a lot. so in the end it's really all about the connection, the button, everything else is just details and tuning, but without the on off, no vape
ecigs or pv's or mods or whatever you want to call them are all about one thing electrically, and that is on off on off so in the end it's really all about the switch....
that is also the biggest difference between a mech and an electronic device, the way it switches on and off
the mech mechanical connection basically touches 2 pieces of metal together to close the circuit and allow current to flow. each time a mech is switched on by pressing the button there is an arc as the connection initiates current flow. this button must flow all of the current so it needs to be substantial. the button is one of the most important parts of any mech.
the connection when perfectly clean and not oxidized allows current to flow straight from the battery to the atty at battery voltage, minus any resistance in the circuit that is the mod. this connection point that controls on off every time degrades as you use it, arcs cause oxidation and oxidation causes an outer crust of oxidation on the metals surface, microscopically at first but it builds up and builds up until it starts to restrict the current flow. it can eventually get bad enough that you start to hear the term misfire, that's when you press the button to initiate on but the connection has degraded to the point that it doesn't even let much current flow at all, so you then start pressing the button harder and harder to initiate contact and eventually you take it apart and clean up all the connections, hopefully put a dab of anti oxidizing grease on there and the cycle begins all over again.
as the connection degrades so does performance, a high resistance connection point for on off sucks power from the battery just like your atty does so battery performance suffers and the vape suffers. everyone with a mech knows how it feels to have the contacts degrade to the point that the mod is working like crap, then take it apart and clean up all the connections and put it back together and say, ahhh, that's how it's supposed to work

but again the cycle continues and the connection starts degrading right after your done cleaning it.
some higher end mods address this with exotic plating of the firing pin, stuff like gold and silver even rhodium plating are done to slow down this process but nobody has made any batteries with gold contacts so any mod that's doing it's on off switching by making and breaking direct contact with the end of the battery itself is going to experience this degrading performance more so and need to do some periodic contact maintenance and suffer degrading performance at times in between but even the exotic contacts that are remote from the battery ends still eventually need maintenance and performance still degrades with use.
an electronic on the other hand does not rely on a mechanical connection at all for this on off.
on an electronic device this on off connection is done inside of an ic chip. the connection can't degrade or oxidize because it is encapsulated in an oxygen free environment inside the chip and the on off always works consistently and is always at peak performance and never degrades. since the ic chip is remotely controlled the actual switch of the mod doesn't have to be substantial and doesn't have to carry any of the current itself so it can just be a smaller clicky button type switch that always works every press, never misfires and never degrades in performance and never needs to be pressed harder and harder, never needs maintenance and never winds up getting to the point of working like crap because it needs to be cleaned.
one thing I find funny is that many who prefer mechs claim it's because of reliability but in reality a electronic switching device is way more reliable and consistent from on off to on off vape after vape, def more reliable and consistent from battery fresh off the charger till almost dead
the main difference is the way it switches on off but the fact that you can now also vary the amount of power it outputs is a really nice bonus you get from most electronically switched devices. reliable switching and variable power output control.
I like and have both and prefer my vv vw devices for day to day use because of there reliability and consistency of vape but then again I also really like the simple mechanical sleekness of my poldiac too, so I wouldn't say one is better than the other, there different and they both have there pro's and con's, but the switch makes the mech, get a mech with a good switch at least if your gonna go mech