(Image credit: Future) Andy Edser, hardware writer (Image credit: Future) This month I've been: Testing an extremely heavy keyboard while benchmarking many, many graphics cards. Also, a spot of overclocking . Nothing caught fire. Victory! When I first learned of the Keychron K2 HE Concrete Edition , I was both intrigued and confused. On the one hand, I was aware of the existence of the standard keeb and that we'd given it a massive 88% in our review . The addition of a concrete shell for extra heft? Sounds interesting. With a description like that, I knew I had to try one for myself. So, I duly requested a review sample, and boy howdy is it heavy. Its 1.74 kg weight was compounded by the fact that my test model was sent to the office, which meant I had to stick it in my backpack to take home. On the train. With a long walk home from the station at the other end. Article continues below I am not a clever man.…