Gary, I have not yet but if it's anything like their other motors I should be pretty happy...
ForcesR, I have the Merlin II twin and it's shaken itself apart twice post a rebuild by John Clark ($1500 US). I've just shipped the motor back to Canada again (3rd time) as the front cylinder is floating and the center section is loose again.. When it was running well it was very underpowered with his 3blade 24X10 prop... I'm guessing the DA100 will produce 50 to 75% more power and it'll swing a huge 28X10 2 Blade or a 24X12 3blade Mejzlik CF prop...
I've asked Darryl at Sierra if he can create spinners for me... I couldn't find a 6.5inch Spitfire spinner anywhere (Gene Barton has one for a P40, TruTurn has a Ultimate one)
I just sent the motor back to DA as I hoped to use the Merlin II's exhaust but the carbs on the DA are in the way... I'll put a faux header on the left side and have both cylinders feed into the one on the right...
wish me luck..