The thumb button in all its forms is a great addition that gives the G502 X that bit of extra customisability. Pair that with the fantastic thumb rest, longer buttons and you have yourself a superbly ergonomic mouse that boasts improvements we didn't know we needed from the Logitech G502 line. I can't say there's a lot to complain about with this one. I personally regarded the previous model as the perfect mouse, and it's almost a shame to remove the weight it had behind it, though I do admit the ergonomic changes are likely better for my hand. The new ergonomics do have the potential to alienate those with larger hands or who don't enjoy the sideways slant, and the weight reduction has meant RGB likers like me would need to spend substantially more. But FPS players with average sized hands are likely to be over the moon with the G502 X. The wired version here is the evident choice for the sensible and frugal among us, and the wire actually doesn't create a detriment to the usability. It's long and flexible enough that it doesn't get in the way, and although it's not braided like some of the previous model's cables, it doesn't snag or curl up. The major difference comes in the form of the angle of your hand. While my initial qualm was that the lower profile shell meant my wrist was leaning on the desk a lot, my hand has now shifted around to the intended position. I get it now. It's slightly skewed, similarly to those vertical mice that are all the rage at the moment in offices, which gives it superior ergonomics to the simple flat, front facing hand placement of the original design, without it taking an age to adjust.