As title, had some new wheels built last Summer (Mavic 819s on Hope Pro IIs) and Santa brought me some High Roller LUSTs, so time to make the switch.

My understanding is that it is not essential, but wise to use sealant(?) If so, which are best in your experiences?

Thanks.

imo if you're going to bother with tubeless it's by far better to use sealant – thorn type punctures cease to be an issue, in addition to pinch punctures being much, much rarer.

i use wheelmilk from JRA – had no issues.

some like stans better for sealing larger holes, but it does dry out/ball up faster, and wheelmilk copes fine with thorn type holes.

You will get a variety of answers!
Stans
Wheel Milk
Bonty Superjuice (Bonty tyres only)
Hutchinson Protect-air
Geax somethingorother

I've tried all the above with varying results (Stans worked out cheapest)
Geax lasted longest.

Others will tell you to make your own with latex and mountain goat sperm.

JRA Wheel Milk worked for me.
But went back to tubes eventually after big burp & blow-out drama.

don't matter, they're mostly the same.

I've found Stans seems to dry out a bit too quickly for my liking. Will prob go back to JRA when this bottle runs out. Obviously YMMV.

I've always found Wheel Milk to dry out incredibly quickly, sometimes within a couple of weeks, which just makes it a nice ineffective weight in the tyre.

Stan's is far and away the best IMO, never had it dry out even after months.