You don't need an "octane sensor", and the only place I can imagine you'd use something like that is in a flex fuel car where stoich is wildly different.
The knock sensor is the great foot that stops the engine from being damaged. If you get bad gas, the engine can retard timing on the fly and even add fuel. Obviously, you don't want this to be happening, because you'll be losing power. But all things being equal, you can run a 93 octane map on 91 octane gas, you'll just make less power than you would on 91 because the quality of the gas is poorer than what the ECU was mapped for.
Also, don't be afraid of higher timing and lower boost, because that's how all these cars come from the factory. They run a ton of advance up top. When you bring the boost up, you need to bring the timing down. There's not a perfect recipe, and every engine is different.
The way Unitronic does things isn't inherently more dangerous, *unless* there is truth to this knock sensor deadening. If there is, all bets are off.
The lower boost in the midrange is going to account for the less midrange pull, and exacerbate the hyperkinetic nature and high rpm acceleration feelings of the engine up top with the K04, since there's some torque missing there.
If you really want to know, bring the cars to the track and see which has higher trap speeds.
To me, the style of tuning isn't in question re the APR K04 fiasco, the partial throttle drivability is. But I've heard they're revising the tune, and hopefully those customers having issues will be addressed.
