As per the title, I need two sets of tyres, one for the UK Winter, and one for the Summer, the Summer tyres have to be fast rolling and suitable for the Kielder 100 (assuming its dryish).
I have tried Bontrager Jones ACX and I was never happy with how loose the tyre was on the rim, and how easily torn the sidewalls are, I have also tried WTB Exiwolfs.

What are STW suggestions?

Summmer – Aspen or Crossmark rear, Ardent 2.4 or Ralph 2.4 front

Winter – Bonty Mud-X rear, Mountain king 2.4 front

Works for me tubeless in the North East on a rigid singlespeed set up. Prefer the Maxxis for sidewall strength and tubeless set up over Schwalbe.

Obviously your riding style, weight and set up may vary!

got crossmark front and rear on mine at the moment but i'll be keeping an eye out for winter recommendations.

Bonty Mud-X for the winter, brilliant wet mud tyre, Crossmarks in the summer. Have also Got Stans Raven/Crow front/back mix on at the moment. They are very light, roll brilliantly at 20psi (tubeless) but I can't help thinking they will be a bit fragile for your average trail centre…. no problems with them yet, but I tend to stick the Crossmarks on for rockier stuff.