So what is the go-to hydraulic set up of the moment?

For XC use, ~85kg me on generic 29er weight bike.

Simple deore still good, or do I “need” hopes etc… I have a limited budget.

All opinions welcome!

(Only previous experience is old Mono Minis, seemed ok, and ?Deore or similar shimano that I can’t really fault but squeal like mad/catch dirt and make annoying noises)

SLX are alway a winner! I’ve had them on all my bikes from my free ride rig to the shopping hybrid

+1 for shimano, or though I’d suggest picking one end of the spectrum. Having just bled my partner’s Doere brakes, I’m stuck to find any discernible difference from the SLXs. The XTs are only marginally more expensive so I’d say XT or Deore!