A901E is the improved version for European market. I have both models and I find that E the motor runs significantly better more stable. What a shock difference. Wish I have known earlier.
If you have to do repairs there is a difference in the parts from Ebay UK so make sure whether its for A901/A901A/A901E/A901P
There is also a P model which I came across on internet but not seen anywhere.
According to this webpage
http://kenwoodchefrestore.co.uk/Kenwood%20Chef%20Models1.htm
A901 is 375 watts and A901E is 450watt
This is a great website as its has compatibility of attachment charts.
This is service
Wee Lee Wong, August 2014