I've done a couple of flights in the Piston Duke now and I love it. I was struggling to fly it accurately but I think this was related to MSFS weather / turbulence because the aircraft was all over the place, the nose constantly dropping then bucking and the ASI gaining and losing 10 to 15 knots every ten seconds or so - with 'normal' / offline weather it was better...
I found some power settings to help fly the approach which is where I was really struggling and found that approach flaps, max RPM and around 15-16 in. MP gave a nice descent rate and approach speed and likewise with full flap bumping up the power to around 21-22 in. MP also worked nicely.
I've upped my failure rate now and look forward to diagnosing some issues soon. I did get a vapour locked engine recently and didn't manage to get it cleared and started but I was very pushed for time.
I'm struggling to find the desire to fly anything else right now :-)