Some of my lights wouldn’t have switches if they didn’t have side switches.
I like side switches if they are countersunk so that the light doesn't constantly turn on in the holsters. DX80 being the most guilty of this. Even with it in e-lock, a microbe could set that thing off in the holster.
Depends on the light. IMO side switches are more suited to mid-larger size lights and are better for navigating complex UI’s.
On smaller edc lights I prefer tail switch, ‘simples’ 
I like both. Just depends on the from factor of the light. Bigger head heavy lights benefit from a side switch I think. Keeps the light better balanced in your hand I think. I don’t understand the whole “I have to have a quite switch ” thing. I am getting ready to fire up a few hundred to a few thousand lumens. Why does it have to be silent? I can light up a whole room but damnit I don’t want you to hear my switch. Makes no sense to me, but, hey, to each their own. In some more complicated UI’s I find it easier to navigate and set options with a side switch. Tube lights, S2+ style, I like rear clicky’s.
For wide diameter/pistol grip/top handled type lights i’m not likely going to fit in a pocket I’d definitely want a side switch, Whereas pocket carried /vertical carried I’d go tail. If reaction time is important you’ll reach tail quicker because orientation isn’t as important imo. Whatever your application prefers ymmv
Being a light painting photographer I’m not a fan of side switches (at least for on/off) as they are not accessible when in the connectors between the flashlight and light painting tool. Give me a tail switch any day! Not a problem for larger lights used for illumination only such as the Q8 though.
I prefer side switches over tail switches because when you hold the flashlight normally your thumb is always right at the switch, without having to change your hand position to reach the back every time.
Easy to turn on/off or change modes.
Fumbling or dropping the light is easy when you’re trying to switch from one grip to another with a single hand just to press a button once.
It’s not hard to find a switch on the side of a flashlight because they are often made form a different material than the body, such as rubber, and also textured.
You can literally just grip the flashlight and immediately feel where the switch is.
The more options I build into my firmware,the more I appreciate e-switches. Meanwhile the UI is so feature rich that it can’t be used with a clicky anymore in a reasonable way.
I’m all for e-switches as they enable much better UIs.
But location is a separate matter. Tail e-switch:
- is harder and costlier to do
- takes more space
- may be less ergonomic in use
- but is easier to find initially
I’d like to have a light with a tail e-switch. But so far this is not enough to make my buy FW3A. 
Klarus G20…?
Thanks pinkpanda3310, that’s interesting. I think I’ll take a closer look at a later date. Which means “look and read” rather than “buy”, I’m not into flooders unless they are tiny and this one is too not interesting enough to make me reach to the pocket.
I like flashlights that take one Lithium-Ion cell, and for those, rear tail clickies make the most sense to me.
I don't like it when flashlights turn on in my pocket, which is a problem with side switches (and twisties.)
I’m slowly changing over all the lights to Side sw.
Tail switches annoy me no end.
You lot will also find. As you get older and your thumbs aren’t so flexible. Tail switches often take several grips on the bloody torch to get the angles right to operate the things.
Side switches. 30–100 are ideal outside. with 2–30–100% for inside.
ANY flashes do nothing but annoy me.
ALL torches should have the 1\4 turn tail cap to isolate the battery. and twisties I find are the best for thoce tiny little ones.
I am one of the few people that feel each light has a purpose.
Some need tail switches and some need side mount.
Twisties are almost worthless… Well except Veleno Designs Quantum D2, it is special…
What no Twisty LOVE
I like both tailswitch and sideswitch equally… it depends on the light.
^THIS^ +1,000,000……infinitum…. Aging hands are definitely a factor. Burning, Stinging, pangs that can shoot from hand/wrist/finger joints to the bowels of hell in a split second. I have both configurations of switches…side switches eliminate the pain though…. Getting older can suck …. :disappointed:
I like the side switches but the parasitic drain and sometimes being hard to find in the dark can be a problem.
As usual get both.
Twisties represent!
Just because a switch is on the side does not mean it needs to be an e-switch.
This topic is not about e switches vs physical switches, it is about tail vs side.
Also if the light is designed well then it takes the same amount of time to find a side switch as it does a tail switch, assuming you have working nerves in your fingers.