No, 300 baud. This comes from a direct quote by Bill Joy[0]:

"No. It took a long time. It was really hard to do because you've got to remember that I was trying to make it usable over a 300 baud modem."

[0] http://www.theregister.co.uk/2003/09/11/bill_joys_greatest_g...

Although you're technically correct (since baud connotes the rate of change of the signal and not the rate of data communicated over that signal), modems didn't start sending more than one bit per baud until we got to higher data rates. At the time vi was written, 300 baud was in fact equivalent to 300 bps and the terms were used interchangeably.