Polestar being a factory sanctioned, dealer installed, warranty covered thing, I think puts it in the low risk class.I'm also looking at potentially going for the P* upgrade on my V60 T5, however I'm still in doubt about engine reliability (pumping even more out of the 4-cylinder engine is that smart?). Any thoughts on that?
Strangely enough when I asked my dealer's technician he was not very convinced that the P* upgrade would make the gearbox much better in terms of shifting (I think the shifting sometimes lags when you need it to shift quickly on for instance a takeover), it seems with most of the answers here that it does actually make the gearbox better. Interesting.
The drivability will be up to you, if you value the improvement in response and shifting. I can totally see how anyone could drive the upgrade and say "meh I can't tell the difference", like I can't imagine on what planet my wife would ever say "The Polestar software is great!" ha. But me...oh yeah it's totally worth it, but I am tuned in and care about such things. So probably only valuable if you are more than casual about driving and your car.