Busted on a track day running roughly 550 whp at the time. Now, I'm not sure if the damage was done prior or I did something that day. Maybe a shock load over a ripple strip. I haven't pulled it down to have a look yet. The new box should be here soon so I'll know what failed soon enough.
There is a bloke in WA that has busted two of these OS sets with a 2.8 and low mounts also.
After 12 months of research, talking to guys and manufacturers of gearsets, I chose the OS88. Yes, it's a lot of coin, but good luck breaking that.
By the time you do a PPG 5 speed for example with all th fruit you're almost at a 6 speed sequential anyway, AND you're not still dealing with the stock gear case.
Food for thought?