ATTQOTD: I guess the answer is 3? When I started, I was running away from zombies using the ZombiesRun app on my phone (still do) and I've been wearing a Fitbit for years, longer than I've been running. I'm currently on the Fitbit Blaze, which isn't available anymore but has been chugging along for 2 years. Just had to replace the watch band but the electronics are still going strong, and this design actually makes it easy to replace the band, compared with the ...4... previous Fitbits I've gone through.
When it was really clear that I was serious about the running though, I started looking at GPS watches. My husband "gave" me a Garmin 735xt for my birthday last year, except slightly early so it was on my running birthday (and also because I wanted it to wear while running in England, where my phone tracking wasn't going to work well because of a lack of data signal). He likes it because the Garmin live tracking lets him see if I've finished my run and have just forgotten to IM him that I'm back at the house. (I run in the mornings, after he's left for work.) I like it because, well, GPS watch.
I admit the Fenix 5S is really tempting, but I've only had this one a year so I will simply drool from a distance. As it is, I'm wearing the Garmin on the right wrist and the Fitbit on the left. If I were to get the Fenix I'd probably want to wear it more often (I only wear the 735 while running) and that would mean wanting to switch the Fitbit to something smaller ...like the Alta HR...
I may like gadgets in general.
On the plus side, it was really easy to sync my Garmin runs automatically. I had been keeping everything in Runkeeper up until I got the Garmin, but then I switched to Strava and loaded everything in there. (Everything still gets loaded into Runkeeper too as a backup.)