Thank you everyone for your input!
I will probably go with the consensus that is SLX. I think sofaboy73‘s point in particular — about the feel being different — is very valid.
Let’s face it, I think SLX would be considerably better than the bottom end BR-M355 Altus stock discs.
While I’d enjoy knowing I’ve got the power I’m not sure I’d be pushing enough to use it all. And I certainly wouldn’t want to go over the bars accidentally either!! The SLX leavers with the adjustment knobs look slick ;-)
For cost savings I’ll go with standard rotors too.
Now, I can max go to 10spd without changing my rear hub/wheel…
A Zee crankset is cheaper than SLX — looks a load better IMO — and comes with the Hollowtech II BB which I’d need to boot!
But.. should I match it with a Zee shifter and derailleur (SLX 10spd cassette) or go SLX there too? Not looked into the cost implications of this yet but I think Zee is a little cheaper on CRC.