my Iron Man has full LED kit and no flickering at all unlike my creature which has some ghosting as only part of the playfield has led's but not the ablaze 3's. IM looks awesome with LEDs - with the Ablaze 3 and 9's used which are designed for flashing and GI lighting.

http://www.pinballlife.com/index.php?p=catalog&parent=192&pg=1

Though in my pop bumpers were the ablaze 1's and they don't work at all and then replace it with a ablaze 3 and it works.