Beauty is in the eyes of the beholder, the phrase cannot be applied any better to the many expressions on plastics preferences for keycaps that have been shared here and in many other threads related to this topic; which, by the way, is one of the most discussed one; however, facts are beyond feeling and personal preferences, first, not all ABS key caps are made equal and, in particular, thick key caps made with double shot molding process tend to provide a great tactility and long lasting legends; second, PBT and ABS are different polymer compounds that provide different mechanical properties to the parts made of each one, no one is intrinsically better than the other, both are thermoplastics, ABS is amorphous and PBT is semi crystalline and it provides double the tensile strength resistance than ABS, but this is five times resistant to impacts (Izod Impact) and cracking than PBT. Being the other mechanical properties similar, it is clear that PBT is more fragile and hard than ABS which is more flexible and resistant to impacts, which are the main actual differences that may be perceived with the finger tips while typing, PBT feels dryer and will tend to keep its texture longer, while ABS feels softer and tend to loss its texture with less usage.
