My FS & HT are both 3×9. Granny ring for the steepest climbs, middle ring for most singletrack, big ring for descents and road sections. I don’t understand people who claim front mechs are difficult, that coping with two mechs at once is hard. Do they have trouble with other multi-tasking situations, like walking and breathing at the same time ?
I also don’t believe weight saving being a big part of the change to 1x, because weight doesn’t seem to be any kind of concern anywhere else nowadays with trail bikes generally being 30lbs or so. My HT with one of those OMG IT’S SO HEAVY front mechs still comes in under 20lbs because I do care about the weight of everything.
I changed my wife’s bike to 2×10 only because a cheap groupset came up and I’d already been planning to upgrade the cheap rubbish that came as stock. She just leaves it on the big ring all the time. In the garage. It never actually gets ridden so any benefits are moot.
Modern road bikes, I’ve got two 2×10, just because that was current when I got them.
Retro bikes, I’ve got 3×8, 3×7 and 3×6. I really ought to get properly retro with a 3×5 🙂