The same plugs were cleaned by "Ustaad G" about 6000 km ago.
The tips on new Iridium plugs are not like these, they are straight tips. The lower tips of these plugs you see in pictures are actually shattered/expanded, I don't know the word to use for it but the tips are not round anymore, they are like when you hit needle with a hammer and it expands out of shape.
I actually took a picture of old and new, comparing them side by side. The angle is a little off but you can see the difference.
As for feeling any difference after installing new plugs, then there might be during acceleration but it just might be psychological thing, lol, since its new plugs. Will see if I get any difference in mileage (@StrikerX like!)