Here are the logs, but I only recorded the 3rd gear pull so not sure if these will show much.

Oh sn@p! :banghead Well here is a comparison dyno between the pre and post spark plug change. Doesn't look like I recorded the cleanest run due to the power curve at 5100rpm but it shows a noticeable improvement using the same mild tune. I'll check the plugs from time-to-time and change to the ITV20...

Thanks for advice about the change intervals. I didn't know there was a big difference between the brands. I ended up getting Denso ITV22's as they were half price of the NGK's. (stayed with the OEM heat range) I don't know what the prev owner did to have plugs like that, but I agree, something was ...

Hold that thought... I think I may have found my issue(s).
After cleaning the throttle body I then pulled the spark plugs. (see pics)
I'll replace these bad boys and see if the hesitation still exists.

Here is a log I captured today whilst cruising around 100km/h. The car feels like it has a slight surge every few seconds. The road pitch did change every now and then which could impact the readings but the last 10 seconds was very constant so should be a good area to look. The RPMs seems steady, h...

That sounds like a great offer. Might take you up on that but I'll need to check out a few mechanical things first. Don't feel the car is running clean yet and it hunts when cruising at 100km/h so I need to find the cause. Got it booked with mechanics in about a week so I'll see how that goes first....

I applied the Octane High Load tune yesterday and re-captured logs.
3rd gear pull was from 654 secs which resulted in 170kW and 364Nm (atw).
AFRs look good.
Is there anything else you can see in these logs that would make you think the car is not running as good as it could?

Is it just me or is the 158kW I got on Octane tune lower than what I'd expect from a stock MPS6?

Ok thanks, so I'll stick to the standard MAF housing tunes then. Appreciate your advice.

Maybe I'll have to try the "Octane High Load" tune now...

I recorded a new run using the "Octane 3 inch MAF" OTS tune from cold start. (see attached logs) 3rd gear pull was performed at 647 secs. Results were underwhelming, as expected. (139kW and 287Nm but it looks like this tune only runs 12psi which tapers down to 10psi so not a fair compariso...