[Graham]

A few things I like...

• minimum tyre diameter rather than 'tyre diameters within 1mm of each other'
  
• free motor orientation
  
• free choice of motor right across the motor list for all classes
  

...just need to find decent 8mm wide tyres for the Stude' which was raced last Thursday on 10mm tyres

yes I think that because of the diverse range of tracks I would like to see used for this proxy, it will make little difference as to what type or orientation the motor is.
On the otherhand there is likley to be more plastic than wood routed tracks, so motor magnetic traction advantage could be more prominent, and more careful consideration as to what motors remain listed. A few of the old favourites have been withdrawn due to being "out of step" with the majority of those allowed on the list (on my measuring device all the motors must now be under 2gm*cm magnetic force whereas previously it had been under 3gm*cm)