I'm another Martelli mat lover, I have the small and the large. Until you use one, it's impossible to understand how much better they are. It's almost like they have a padded layer between the two sides. They are reversible, with markings on both sides, and are quite heavy. They can be rolled and won't crack, unlike most cutting mats.
If you go to there web site, be sure to sign up for the Red Line Specials, not just the newsletter. Red line specials are the monthly sales; if you sign up they will send an email each month. Sometimes it's a % off a specific item, sometimes it's a % off of anything. That's how I bought each of my Martelli items; they only thing I don't love is my strip cutter.