That said, I tried these modems with a bunch of others that I normally work with. On the whole, both modems worked well, although I experienced more quirks than I would have liked, and I'm now fluent in the Hayes command set. I connected to (as far as I know, and with the highest speed I could reach after each one) a Telebit TrailBlazer Plus (2,400 bps), a Telebit T2500 (v.32 = 9,600 bps), a Telebit WorldBlazer (v.32bis = 14,400 bps), a US Robotics HST (2,400 bps), a US Robotics Dual Standard (v.32bis = 14,400 bps), and several other v.32 and v.32bis whose manufacturers I don't know. Both the PPI and the Supra connected equally well and transferred files equally well to all of these modems with one exception. For some reason I couldn't figure out, the Supra would not connect to the WorldBlazer at v.32bis. Instead I had to lock the connection speed at 9,600 bps (v.32), after which it worked fine with the WorldBlazer. That may be a quirk with my particular setup, or it may have been fixed by one of Supra's ROM upgrades since then.
In both cases, using ZMODEM to transfer files over the fastest possible connection satisfied my longing for speed. Uploading 30K issues of TidBITS, which used to take about 90 seconds at 2,400 bps now takes about 11 seconds. Massive QuickTime movies and HyperCard stacks might take fifteen minutes, but you'll be hard pressed to download anything for much longer than that. Gone are the days of hour-long downloads.