Got to follow suit – my Deore’s are better than they have any right being – super tough, super reliable and work beautifully.
SLX adds finned pads, okay on a dry day on fast trails yes, but on an average drizzly day in Wales – nope, anyway you can simply fit them if you want later – they’re cross-compatable. They also have tool free lever point adjustment – personslly I set this once and leave it – but failing that I’ve got an Allen key in my bag.
XT have the above plus they use a bolt rather than a split-pin, I’d be tempted by that – split pins are faffy – do they come with ceramic Pistons too? Either way, 4 days, run after run in the Alps without fins or ceramic anything and my Deores laughed it off.