Iridium plugs are far superior in spark technology. More intense SPARK! I have a GS 1150 ADV and 999S both live on Iridium spark plugs.....only the best for my girls!
In my opinion, Iridium plugs start better and some cases (like Ducatis) bikes starts without throttle advance (choke being pulled out - old speak). So yes....BUY THEM. They're only about £2.50 per plug dearer.
PS. If it's a twin plug. There are 2 different Iridium plugs.
the plug is temp rated by the number ie cr8eix is colder head running temp than cr9eix the higher the number the hot the head
ngk dealers have chart in plug fitting guide
so cr8eix is same temp as the cr8es