I had been having problems keeping my rear brake pads on the minuscule lip inside the calipers, so after replacing them twice (Autozone pads, for reference - almost an exact fit but that 1mm makes all the difference) , I thought there must be a better way.
When I came across a lengthy thread on here regarding the D110 upgrade, it seemed like it made sense to do since it was time to replace my rotors anyway. I haven't noticed a marked improvement in braking, but the pads now stay in place since they're actually physically pinned instead of pressed down by a spring. That alone is worth the swap. And technically, it's the D110 front setup installed on the Disco rear:
Front Non-Vented Setup(requires bending of hard line from flex to caliper)
Caliper: LH: RTC5573
RH: RTC5572
Rotors: LR017951
Pads: SFP000260
Fitting kit: RTC5001 (as per Zach at Rovers North)
THE thread:
https://discoweb.org/index.php?threads/110-rear-brakes-on-a-d1.94988/
So if I'm going to do all the work involved in replacing the rear brakes anyway, it made sense to me to replace them with easier to maintain brakes for the future. And for the original poster, replace the bearing seals while you're at it since it's all open to the world at that point.