My advice would be to be to leave the SPDs at home, the section along Cowlyd gets quite technical, if you do wear them expect to be clipping in and out.
Did it anti-clockwise and can confirm the road climb out of Trefriw is a killer, iirc it’s something like 450m hight gain over 2km.
+1 for the lakeside cafe at Crafnant, must be one of the most scenic in the country, might still be open if the weathers nice.
It’s pretty remote so if your doing it on your own tell someone where you are going.