The problem with external modems is that the serial ASIC and the modem ASIC are not integrated, and that can lead to some dropped data at high speeds. Mostly, this is irrelevant, as other protocols deal with it, but it was an issue.

Then again, finding an internal, non-Winmodem modem, especially if you need PCI, can be a real challenge.

By the way, if anyone out there thinks that Winmodems don't suck, try running one off of a phone line that's coming through a PBX. Then swap it out for a real modem and see how much better it works.