I have Olfa mats and Fiskars, same with the cutters!

I prefer my Olfa, and one of my mats is 15 years old! It is still just fine to use, and gets lots of use and love. I have had he same rotary cutter for just as long and adore it.

My Fiskars mat works fine, but it feels stiffer, or harder, compared to the Olfa, and so I think that would dull blades more quickly.

As for cutters, I like the ergonomics of the Olfa more than the a Fiskars, though I really think this is a personal fit kind of question. It's probably that I like the weight and feel of my ancient Olfa cutter because it's what I learned to rotary cut with all those years ago!