Tried standard bosch, plasma, splitfire and denso iridium.
All except plasma are trouble free.
Plasma got clogged up pretty quickly. Engine was super smooth until clogging happened.
Splitfire seemed to give more torque/power but engine seems a lot smoother with the denso iridiums.
Note that Denso iridiums come in long life version with a 0.7mm tip and performance version with a 0.4mm tip.