I've been vaping a Mako Midi for over a year -- closer to 2, I think (I don't keep track of stuff like that). My #1 reason for a purely mechanical mod (APV these days

) is simply that when you let go of the switch, it's off. I toasted 2 Rivas in fairly quick succession, and they both failed the same way -- I hit the button and took a draw, and the regulator circuit fried itself in the ON state, so I had full battery voltage going to the coil. Only thing to do was unscrew it. The 1st one, I didn't catch right away, and I got that nice burned insulation smell.
That said, if you have an atty short out, and you're running Li-Mn batteries, you'll be pulling some serious current. But the risk of that is mitigated by the simple expedient -- as I said -- when you let off the switch, it's really off.
Now, I don't know about other regulated APVs. Maybe some have switches that completely disconnect from the battery in the off position. Those would have the same advantage, but still with the possibility that the electronics could fail. I hope that most of the regulated APVs around have better quality circuits than in my 2 Rivas. Still, with a pure mechanical, that issue is just not there.
And even if you spend some bucks on the APV to start with, you recoup that over time, because you're just buying batteries from then on. I've vaped my IMR 14500's down to 2.5V, and still had them last a year or more. I keep 4 in rotation, and use 3 or 4 a day.
Used to be, ElectronicStix in AZ carried the Mako and Megalodon, but I think these days, the only place to buy them is Moju Republic, in England. The Mako is robust, and needs little maintenance. Fully disassembling the tail switch isn't too bad. I did modify my top cap, which was simple and cheap. i have the v2, and I don't know if the v3 would benefit from the same tweak.
If a pile of money showed up, I'd be looking at a Precise from Super-T.