I would go Shimano Deore M5100 1x11 that offers 11x51T and supports the HG+ tech of the 12s Deore line, while being still HG hub compatible.

 

Very good point you make. However I've already got the 12 speed Deore components so I'm committed to going the 12 speed route.

 

Doubt any cassette or chain combo is going to perform noticeably better than another. With these parts being consumables suppose the obvious choice would be the cheapest option.

A Shimano 12 speed chain being HG+ design may be better suited with the Deore chainring but maybe not so work as well on the Sram or Sunrace cassette?

Sunrace cassettes are good quality in my experience and well priced compared to Sram or Shimano. Can't say I notice any difference in shift performance, compatibility or durability between chain brands whatever they cost.

Currently running 11 speed Sunrace cassette with a cheap Sram chain combo and it's working perfectly well together.

 

I would ( and have ) go with a Sunrace cassette.
It's cheaper and lighter than the NX cassette and the 11-51 is made for Shimano ( but not for HG+ chains )

I run a 11-51 with a GX Eagle chain and Deore 12 speed mech and shifter.
Pretty pleased how good it works, but the adjustment of the B-Line on the derailleur is a bit different on Sunrace cassettes than Shimano ones.

Also I would stay away frome Shimano's 11 speed 11-51 cassettes.
Too many reports of bad tolerances and broken rivets. Not just in this forum.

 

Also I would stay away frome Shimano's 11 speed 11-51 cassettes.
Too many reports of bad tolerances and broken rivets. Not just in this forum.

Really?
Completely unaware. Would love to see more / will look into it.

I had two bikes with the M5100 11x51T cassette/drivetrain (one OEM, the other upgraded to from a M6000 drivetrain), and zero issues so far.

Granted, I am a weekend warrior and I don't even do 100 miles a month, but so far shifts have been crisp and the cassette looks like new. Shifts are crisp, even under full load.

 

You can see that SunRace here, and yes, no HG+ with it

 

For the sake of not having shifting issues I'd use the Sunrac cassette.

Why? The cassette spacing is different in SRAM 12 to Shimano 12. The Sunrace cassette you identified uses the Shimano spacing. Read about it in this thread.

Shifting issues 12sp upgrade on HT

Shifting issues 12sp upgrade on HT (RESOLVED) See latest posts for updates. RESOLVED 11/21/2019. See post #39 for final update. I appreciate any input. The below is the problem I'm encountering. Downshift (small to largest cogs) adjustments are great; smooth with no hesitation. Upshifting...

www.mtbr.com

I use a Sunrace 903 with Shimano 12. It works well

Other advice: follow Shimano's instructions to the letter. Note that the chain lenght method is different. Also 12sp is very senstive to hanger alighnment...I'd buy one if you don't already have one.