Mathematics and physics seem on occasion to be different on the island called UK.
Anyway I Love my Airline
4 point versus Airline is a close call soundwise, but once you get used to tangential there's no way back. I dare say the Airline is not a 'better' sounding arm, it misses something, which you are not aware of with 4point until direct comparising with the Airline.
Ive set up many 4points at friends, the Airline asks for more commitment in setup and maintenance on the air compressor. I would advise 4point in any situation. The 14" is a very interesting move, maybe it get's closer to the Airline, may be very well the sole intention..
