[HerrKaLeu]

I wouldn't go 1x if it wasn't 12sp and had a 10t sprocket. There's enough range and gear spacing lost when going 1x that it doesn't make sense to make it worse.

I tend to agree, but even with the 463% of the 11-51 cassette many people can be happy with. It sure beats the " old" 1x of 420% for 11-speed SRAM. And regardless of range, 12-speed will give smaller gaps.
And OP could re-use the Hg hub for now, get 12-speed. and later on when OP gets a new hub, keep the shifter/RD etc. and just swap the cassette to MS or xD. OP could time it with the time this first HG cassette wears out. Yes, in an ideal World one buys a new wheelset with carbon rims, excellent tires, fancy hubs etc. at the same time one upgrades the drivetrain. But this is not always practical for everyone

All the other options mentioned here (9 speed, 11 speed etc.) will have the same problem that the real full range is accomplished with a new hub. With 12-speed, one at least doesn't have to replace the shifting parts later.

Nothing better than actually riding and trying. But before that, one can compare the old drivetrain to the new options

 

[goofyarcher]

1 x 10 with advent, I did that on a family members bike it is flawless would do it again to get to 1 by.. it as 11 to 49 tooth.. works great

 

[Amt0571]

I've been riding 1x11 with the Shimano HG style cassette for some time which is 11-44 I think and I'm fine and our terrain is about as steep as it gets.

Honestly don't see any point in spending up to get 12 speeds. Get a smaller chain ring if you are struggling with the bigger climbs.

If you're not walking with a 44, it's not as steep as it gets.

 

[RYMTBME]

4 month update... I am happy with my 1x9 setup. Once in a while I wish I had another easier gear or two available to me but where I ride the most it's not an issue. I plan on getting a new bike (full suspension) at some point (maybe next year) so I don't see putting money into adding more gears. Having a dropper post (PNW Coast Suspension) is great and having the space available for the level is reason enough to get rid of the front derailleur. My next upgrade will be shorter cranks. Been researching and it seems I could benefit from going from my 175mm to like 160mm.