Once you exhaust the lone COM port you are lucky to have on a computer sold within the last 5 years, you have no choice. Even a PCI card operating as an ISA compatible interface is not quite the same, and in any case is limited to 4 possible ports. If you want more than that, you need some sort of media converter. USB to serial is not ideal, but it is closer to to transparent than any of the alternatives.
Totally agree with you.
Actually, for a great all in one tool for serial/parallel comm work I use A21 and T30 Thinkpads. They work great for all my work a day electronics, data logging, CPLD, MCU programming, PLC, CNC comms and programming...and the list goes on. They are rugged, reliable, modular, have quality components and are nice and snappy on a tuned XP Pro install. Extremely versatile, useful computer for all things electronics...and you should be able to pick one up for the price of a Tripp Lite USA-19HS if you keep an eye out. Also, best keyboard feel ever for when you have a lot of HDL or C to hammer out.
Honestly, a working PL2303 or an FTDI chip using the VCP drivers gives you essentially perfect emulation from the standpoint of a user-mode windows application. The latency is considerably higher, but windows doesn't give you guaranteed latency even with a hardware port. This isn't a problem if you are doing normal serial communication, but will totally hose you if you want to bit-bang a different protocol on the control lines. The solution is to not do that. Use a microcontroller to implement the interface and use the serial port to send commands to the micro.
Right, again.
In the end, I think it's more comfortable sticking with the hardware. Sure, it's not perfect, but bit banging inevitably distracts the processor, which is never ideal from an efficiency stand point.