Your never get a concensious of opinion over iridium plugs but many of you seem to miss the point of them.
I had a long chat with the NGK tech at the NEC a while back and he explained the benefits very well.
The biggest being they use 25% of the voltage to produce the same spark as a conventional plug. Forget everything else for a moment and read how many peoples bikes don't start if the batt is less than 120%.
Therein lies the justification in my eyes of the extra £2.
Do they produce more power, Probably not or probably not enough to notice but then does that K&N filter some may have fitted make your bike faster ?
Perception is a personal thing.
I have never noticed any improvement whatsoever from a high flow filter on it's own personally but i bet many have. Perception see, who am i to say they are wrong and i am right if they feel a difference.
Now I'll give you a scenario given to me by the NGK man. Rich bloke buys a ferrari. Uses it every time the sun shines to go to the shops and does 2k a year. Perfect plug fouling, poor starting conditions because the car never really gets the weeds blown out or the batt recharged fully and the next time it don't start.
What do ferrari fit as standard on all their cars. Irrdium plugs.
25% of the voltage over 10/12 cylinders = the difference potentially of starting or not starting.
Apply some of that logic to your bike, and the batt is less than 100% or it's very very cold etc etc. Will it make the difference between it starting or not starting. Who knows, but for £2 wouldn't you want to give it every chance. ?
That for me is the point. You can argue all day as to whether it gives you 01hp more at 5000rpm and frankly who cares but for £2 even a 1% improvement between starting and not starting and i'll take it.
If everything on you bike is 100% then it will start whatever the plug no doubt about it.
My personal experience is touring France at the weekend and my bike develops a misfire (plugs 6k old). Nowhere to get a plug, limited tools etc etc.
I could carry a spare plug or even more tools but why not fit an iridium plug me thinks and save myself the bother. So that's what i did and i have never had a problem since touch wood. I also think the bike ran cleaner generally but we get down to this perception thing again.
If your bike runs fine on standard plugs, :thumbup good stuff.
But mine runs nicely with Iridiums and like a back protector i feel better in the knowledge that should sh*t happen it's an extra level of protection that may make the difference to my days riding.