The Ann Arbor Ambassador was the ne plus ultra at the end of that age, it did up to 60 lines of 80 characters, had the fancy features to minimize data transfer,

The Ann Arbor Ambassador was the ne plus ultra at the end of that age, it did up to 60 lines of 80 characters, had the fancy features to minimize data transfer, and could do it all at 9600 baud. The VT220 was a nice evolution of the clunky VT100, but there wasn't a vast difference from, say, the VT52 to it, besides the extra commands that allowed minimizing data transfer (at the cost of rather hairy redisplay code).