Hi Lee i've just watched one of your other vids on youtube with the Wagtail:
http://www.youtube.com/watch?NR=1&feature=endscreen&v=x-xVT-uNLE0
Just wondered how you are getting on with it now?
I dug my one out of the garage where it's been for over a year.
I used it for a bit today and forgot how good it is. 
Have you tried the new Wagtail PC?? ...... I had one sent over to me by Willie... will do a users review and video very soon 
No to be honest i've only ever used the 14" Wagtail Whirlwind (with blue pad).
In fact I used to find it was just a bit too wide for the majority of domestic windows to get it "wagging" properly.
I have since cut the channel and pad down to 12" and reckon it's even better to use now on domestic windows.