Am finally getting round to replacing my Stumpy frame on a warranty issue, but it seems they replace the shock too. Now this is all fine and dandy if it’s like for like, but the newer stumpies have a ‘brain’ shock on them. Are these the same hideous contraptions that were on the epic or have they improved at all? Are you able to switch off the ‘brain’ function?

Hoping I can just keep the old shock…

I had a 2010 Elite that was replaced under warranty. As there were no alu frames left in stock, they gave me the option of the carbon version with Brain shock.
I took it, and am really pleased with it. If you run it full ‘closed’, you can notice the point that it opens and closes, but you quickly get used to it. I tend to have mine set a couple of clicks from ‘closed’, which seems to all but eliminate any suspension bob, but keeps the rear nicely active.
You can open it all the way (which I guess is equivalent to turning the Brain off), but then it does seem to wallow a bit.

I think the Epic has a much tighter set-up so when the brain is closed, the shock is properly locked out. With the Stumpy, it is never locked out to quite the same degree.

To be honest, the way I tend to have it set-up it feels just like the Triad did under normal conditions; just a lot firmer when you are on flat terrain or stamping on the pedals.

Can I turn off the brain and then set the damping myself like on the triad? I basically don’t trust a valve to decide on the appropriate damping for the train I’m riding.

Only adjustment is rebound damping, which you set regardless of how ‘open’ the brain is.

The brain has no effect on damping.
I don’t know the exact method of operation, but I think of it more as an ‘auto lock-out’ for the rear shock. With the brain set to firm it will take a bigger hit to get the rear end active, and it will return to lock-out more quickly. There is still some compliance in the rear end.
If you set the brain to soft, then it will open the shock at the slightest knock & remain open for longer – I don’t like it in this setting, but I seem to prefer a firmer suspension action in general.

The Triad is basically open, pro-pedal or locked depending on the blue lever position. You also have a twiddly knob to adjust rebound damping.
With the Brain shock you still have the rebound damping twiddly knob, but the Brain works as an equivalent to the open/locked/pro-pedal lever.

95% of the time I would leave the Triad in pro-pedal anyway so I didn’t feel I was losing much by replacing it with the Brain.
In practical terms, I just get on with riding it. It took a few rides to tinker with the ‘firmness’ setting of the Brain, but now it’s set I don’t even think about it. It just seems to work. I don’t really tend to fiddle with settings endlessly though. Once it works, it works.