What is the quality of these keycaps (and similar SP group guys) compared to e.g. imsto PBT? I ask because I've never used anything except for stock, ****ty, thin ABS and imsto thick PBT – I'm seriously considering getting in on this GB, but I don't want to have to immediately resell them because I'm used to different quality. (For all I know though, these feel better than imsto PBT; I know that some people do prefer ABS.)