There’s not that much in it in terms of anything really, other than arguably the 46-50 difference.

Some say 12sp are more fussy to setup, but IMO there’s either setup right or wrong, whether it’s 11sp or 12sp, right is right and anything else isn’t…. Once setup correctly, it’ll work.

I have xt 12spd but while I love the easier gearing I have a problem with the chain dropping off the top jockey wheel. It happened regularly on the XT mech till it blew up, it also happens on the SLX I replaced it with.
I did let the chain wear out without spotting it so I am running it till it dies, is the worn chain the reason?

There’s a pretty big gap from 2nd to 1st on the SLX/XT 11 speed cassettes.
If going 11 speed look at a SunRace 11-46 or 11-50. Much better spread of gears.

I’ve got XTR (10-51) 12 speed on one bike, not even had to adjust cable tension in nearly 3 years of ownership, bloody brilliant, chain wear is immense IMHO, 1800k before I had to change it.

I’ve got X01 / GX Eagle (10-50) 12 speed on another, again it’s been flawless since I’ve owned it.

My eldest has GX 11 speed on his bike with 11-42 cassette and that too is bang on.

Basically whatever you choose, set it up right and keep the chain, cassette, jockey wheels and ring clean and lubed correctly, I use Squirt on everything and they’re all brilliant.

I felt the the 11 speed XT wasn’t a “proper” 1x groupset but just a half hearted attempt.

Pretty much this. SRAM definitely won the 11 speed game but I personally think 11 speed was just a quick 15 minute toilet stop at a grotty service station on the way to 12 speed, which IMO works perfectly (SRAM or Shimano).

my hard tail runs 11 speed XT shifter and mech and 11-46 or 11-50 cassette depending on the wheelset/tyres I have
my FS has SRAM GX 12 speed(well i’ve binned the pony mech off for a Deore)
SRAM just makes clanks and bangs.. I have little faith… the Shimano stuff just smoothly changes gear… I don’t miss the extra gear.. its not like I’m looking for the perfect cadence.. I’m climbing up a hill then dumping a load of gears again.
My lad has 10 speed Deore 11-46 and this too is fantastic, and the cassette only weighs 400g which is lighter than my 11-46 XT cassette I believe. let alone my 11-50 Deore?or whatever cassette it is which weighs a metric ton

basically, i could care less about the gaps on my riding (I don’t even care on my road bike)
but definitely don’t write off 11 speed IMHO

Full Sunrace 12 speed set up with 11-50, MX Mech, MZ Shifter, and a Sram GX chain. All working fine. I’d say that the shifter is a bit more basic than the similar level Shimano or Sram offerings, and doesn’t feel quite so snappy at a Shimano one. That is my only (slightly) negative thought.

I like the very even spread of ratios, and that I could use a standard HG fitting.

I’ve found 11sp to be the sweet spot on my trail bike. Specifically XG-1150 (GX) 10-42 full steel cassette, with any combination of mech and shifter you prefer (I use a X01 shifter and XT(GS) mech).
Combined with a 28th chainring, the ratios are only slightly longer than 10-50 Eagle with a 32t chainring, but with the 10 toot cog removed. While this may limit top speed when pedalling on road I’ve never missed it on the trails.
The smaller spread on the cassette keeps the weight down and improves shifting to and from the lowest ratios, and the the smaller chainring improves clearance over logs and rocks. The full steel cassette also lasts an eternity, in comparison to those with larger aluminium sprockets.

+1

Or if your proper ornery like me, go to the original Advent 9 speed system.

What I’d really like is a wide range 5 speed system…

Check out the reviews of it – have you seen any of it for sale used on here?

To be fair, I can think of at least two reasons for that…

I think coming from a 36t cassette either setup will feel twiddly enough in the easiest gear.

Personally I went from bodged Shimano 11s (XT shifter, Deore mech, SLX 11-42 cassette) to bodged Shimano 12s (SLX shifter and mech, Sunrace 11-50 cassette). The 12s is a bit of a pain in the neck: the mech has holes in the pivot joint so it gets wet and gums up and stops working, and I haven’t managed to get it to shift nicely AND reliably get into the 50T gear. The 11s Just Worked.

So my heart says 11s. But I went 12s this time because it was moar gears for about the same money, and I’d probably do the same again.

Humans are irrational.