I cant decide, I even love my modern Velocity. They all have thier plusses but I think the ones that stand out the most are the 1400 series machines.
Remember them coming out and the hoo haa they caused. The Airstream I think, not because its TOL with bells and whistles but more because it looks smart, seems to use a quieter more gentle motor that just hums and the fact those blue airflow bags just seemed from a different world at the time.