I bought a Mares Matrix computer 6 months ago, I was very happy by the compass and the clarity of the screen. Unfortunately I had serious problems with the push buttons. After 3 months, the upper left button separated from the computer. I send it for repair, had to wait one month and Mares sent a new one. After charging it completely, I wanted to set it up. To my great dissatisfaction the upper right button that is used for the set up (long push) is inoperative. I can press hard for 10 seconds, nothing happen! I may be unfortunate, but I think Mares lack the quality control of company like Suunto, which manufacture very reliable, although expensive computer.
My recommendation: don't buy a Mares Matrix now, wait a year or so in order to have Mares fixed the problem and proposes an upgraded version, or buy a Suunto D6.I