I have the 266dt...I like it because it dosen't have the vent etc, it's very solid...Its very tall, should be fine for a 6 footer...Ebay $145.00
My experience matches John's. I change the height depending on temperature and wind conditions. When it's hot , I've taken the top off to get straight wind at shoulder height. I keep a helmet bag under the seat to store it in.I'm 6' and have the airflow. Can't comment on the non-adjustable, but the airflow completely changed the ride characteristics of the bike for the better. Along with much less wind noise, the stability of the bike is much better.
I have the top part about 1.75 in. Below the top setting.
Hope that helps.
John