Originally struts where just that part that attached the wing to the board. Thin, hydrodynamic and light seemed to be the most important design criteria. .They all looked very similar, more or less..
As wing design progressed, we needed improved ability to transmit the input to the wing for ultimate control-yaw, pitch and roll-, and overall stiffens became more important to designers.
Two years ago I upgraded from the stock Lift mast to a Cedros Project mast (both 91cm.), I was immediately rewarded with tighter radius turns and faster 'edge to edge' control. The increased stiffness of the Cedros mast was easy to feel both on the land (turn your board upside down, place a foot on it and try twisting the wing) and on the water.
For those of us that are looking for longer struts, without sacrificing rigidity, new criteria for design has been embraced...my strut must be STIFF, long (110+) and hydrodynamic...
I settled on the new LP strut (Peter of LP calls it 'the beast')...It's more than stiff, it's ROCK SOLID...111cm, hydrodynamic..and pretty.