Whilst using powermatch on TR on ipad with my 4iiii I also connect my garmin watch and log the power and hr on there.
I realise that TR shows a smoother power than the garmin but it seems that the garmin power is consistently 5% higher or so. I particularly notice this on efforts around threshold where 300 on the ipad displays for prolonged periods of time at 330 or so on the garmin. They are both connected to the same PM.
Just curious to hear if others have found the same, no big deal as my ftp seems to translate to outdoor real world riding anyway.