I decided to change out the ABS keycaps on my Keychron K6 to a side-printed PBT set. They are very thick and comfortable and a pleasure to type on. I got the smaller set and kept the original ABS keys for the extended keys, the right shift, and the number keys with legends since they are not used as frequently. It is something of a "mix and match" set but I think that it looks nice. What keycaps are you using on your Keychron K6?
