I am looking for some new discs for my ss commuter and wonder what discs to get.
Deore
or
Slx
But what is the difference between them and would I notice?

The SLX style ones are supposed to be stiffer and cope better with warping, I think they might also be lighter.

I have used both types and I’ve never felt any difference in braking performance. Just buy the cheaper one.

I would have thought the ONLY difference (other than how they look) is the weight. Im pretty sure Shimano rotors aren’t floating, so the Black spider on the SLXs is purely to save weight.

AFAIK the 52s etc are cheap and soft stamped disks. More expensive and you seem to pay for the extra heat treated hardened ground surface – and can be cut out instead of stamped.

SLX look better, but for a commuter I can’t think of any other useful difference.

(I run them on my SS commuter!!)

The SLX ones in the picture are RT79 (XT/XTR), I’ve had a bunch and it’s the rivets that fail, with the exception of bending the carrier on one.

The RT64 quoted at SLX by Merlin look like this:

I’ve never tried those but they’re ugly.

Get the RT79 or the 6 bolt equivalent, they’re good.