No I haven't stayed at one. I saw their TV ad a few months ago and bookmarked it. The TV ad did say high speed computer access in every room.
This page say that there is a data port in every room.
http://www.extendedstay.com/esa.html
Guess it would be best to call them and find out what they consider a data port.
The last hotel I stayed it, Universal Studios, had an ethernet drop, they called it a data port, in the room that gave me broadband. Not as good as WiFi but took care of my needs. I'm guess that this is what Extended Stay has.