Didn't know there were so many 4 cylinder models pre WW2. I'm guessing that there was a tradeoff between power and handling in those days
For me I have only 1 Unique favorite bike I have been on the track and witnessed it's brilliance in all aspects. Never got near having a ride, but was introduced to the creator by the pilot at the time when we were at Bathurst for the 1993 Castrol Australian TT. That was the Britton ridden by Andrew Stroud. Brilliant rides by the locals Scott Mitchell and Mark Everington beat the Briton. But for a unique part of motorcycle history the Britton definitely deserves a podium place.
Britton was a genious that went way too soon. Motoczysz also had some clever ideas, but did not manage to meet the success of Britton.
Here's a bike not many younger riders would know that well. 1966 Honda RC166 250cc 6 cylinder https://www.google.com/url?sa=i&url=https://www.pinterest.co.uk/pin/74168725091372599/&psig=AOvVaw0wAJXjSo3LWZXlAmttEy94&ust=1616887666918000&source=images&cd=vfe&ved=0CAIQjRxqFwoTCMDFvouOz-8CFQAAAAAdAAAAABAD
Alan Millyard is insane. Talks about his builds like a carpenter would about knocking up some drawers to go in a kitchen cupboard.