I still use it on that hardware for hobby projects, and while I have to wait 60-120 seconds for a compile, it's still more convenient for me than cross-compiling on Windows and then copying the code over.

It's not how well the bear dances, but that the bear dances at all. That said, EMS and a solid-state hard drived do help a little.

TBH for an original IBM PC i'd use at most TP5.5 as it is faster and you do not lose much in terms of functionality (IIRC the biggest loss is the inline assembler).