Boxer, I guess that everyone on the interwebs is a critic.
1. The New Quaife shaft filet is about 0.100" smaller than the chamfer on stock. it looks much bigger on the stocker because the 2nd gear is smaller diameter than the Quaife.
2. The Filet spreads the stress better than the chamfer which is only as strong as the weakest part i.e. the stress riser at the angle at the start of the chamfer.
3. There are considerations for the shift forks etc that have to be dealt with in either case.
The stock input shaft is pretty robust as far as breaking in 2. However, that is usually because high-power cars just strip everyone of the tiny stock 2nd gear teeth off! Ask me how I know......
That said, chamfers and fillets all goodness. It needs to fit in the box and not hit the shift forks or reverse idler etc. etc.
All this without discussing vastly superior steel and heat treat.....
LionZoo, the stock 2nd is BY FAR the biggest synchro in the box. It is the only 2 cone synchro in the box. However, since many people drive these cars as streetlight racers, the 1-2 shift gets rushed and crashes the dog teeth ultimately wearing out the syncho and gear hubs. Better oil like MT90 helps, not rushing the 1-2 helps more.
That said, yes, reducing the gear spread will significantly improve the wear since the RPM drop between gears is much reduced. This means the speed differential the synchro has to deal is less.
I drove our sequential, long-rod car on a brief "test" run on the street. This has close ratio gears. When you start rowing through those upper gears, it is just SICK!!!
Always in the powerband, it significantly increases bloodflow! For drives lasting longer than 4 hours, consult a physician!
Very similar setup in our new synchro gearset without all the herky-jerky of a sequential.