Up to 17 now. I have 16 all setup, fully charged and sporting a different tank and most importantly, a different flavour (although I do currently have the same flavour in my TFV12 as is in my new Reload RTA clone) Funny thing is, the experience is totally different and you would never guess it was the same juice from the same bottle.
Now you might ask why 16 different mods and tanks ? That's mental. (It really probably is)
Well firstly it stems from a particularly bad case of vaper's tongue that I experienced back about 9 months ago. After that I decided variety was going to be key. A variation of flavours, readily available was going to guarantee that I would never lose the taste of a flavour by overuse. (This definitely works !)
I DIY my flavours mostly so new mixes are coming and going on a weekly basis. Some are keepers and some fall by the wayside but the list of keepers (mixes that I can't be without) just keep growing. Add to that, the odd premium juice that comes along and needs a temporary home and you can see how the number of active mods and tanks has kept growing.
Sometimes the justification for a new mod is "I have this beautiful tank with nowhere for it to go"
Sometimes the justification for a new tank is "I have this great new mod and no tank to go on it"
Sometimes the justification for a new tank and mod is "I have this awesome new mix and I love all my other mixes and so need new setup to put it on"
Since I sat here and wrote this I have tooted on six different flavours.
The logistics of keeping this many tanks and mods charged, coiled, wicked and topped up are quite significant but easy once you get a routine going and with this much stuff on the go, If I stopped doing anything today, I could still vape for a few weeks before the last mod ran out of battery or juice.
Another advantage is wear and tear and battery life. Everything will last for ages as they all only get used a little bit each day.
Downside. My desk looks ridiculous