I ordered NGK iridium...then I see here some stating to stay with the platinum because the iridium was designed for lower performing engines (even though iridiums by all data and articles perform better and last longer than platinum). That was nearly two decades with that tid bit. So I'm wondering about peoples experiences with iridium NGK IX in an M35 now. Please provide feedback.

A couple questions on changing procedure.
1/ I plan on changing one at a time and starting up the car just to make sure everything is good and being able to trace an issue easily. Is it OK to do it this way?
2/ I was reading that there are some plugs that I shouldn't put anti-seize on...https://punchlistzero.com/anti-seize-on-a-spark-plug/, can anyone verify this, and would it apply to these spark plugs?
3/ What are tips to remove plugs that may be seized?

Iridium performs fine, and as you said it actually does perform slightly better than platinum as a spark conductor. However, it will not result in any better actual performance between the plugs because the spark plug isnt really the limiting factor and it is so close that the performance difference falls within margin of error.
And yes, many places do say Iridium plugs are supposed to last longer. For some reason though the plugs in the M35 have Iridium plugs rated for lasting 60k miles and platinum plugs rated to last 100k miles. If you look at different spark plugs you will find Iridium's even from the same company with ratings anywhere from 50k-100k. So it really just depends on the specific design, and for our car the Iridium life is rather short.