You have A1200 and you are killing yourself with file transfer over parallel port. Get your self cheap PCMCIA to CF adapter and be done. Transfers takes seconds.
As for you question, many years ago I used PARNET between Amigas and it was at acceptable speed (I dont remember the number), so maybe your problem is with configuration of your PCs parallel port. Check you bios configuration for your parallel port, possible modes are: Normal (SPP), ECP, EPP, ECP+EPP.
