I love taking every chance to talk Iron man so here goes. Been through alot of Pins and for me this is the last to go, a true keeper. Right now i have it next to a TZ and a Tron LE.
TZ and IM are perfect opposites - you know the story there. TZ is the best of the stop/go while IM is the best of the fast/flow.
Tron LE is somewhere in the middle, so i am happy for the balance. Better game? IM by a nice margin. Tron is fun, but IM has something magical.
I also had an SM here. Lots more to do in SM - modes etc, but, not as fun as IM is - not the same rush.
Where IM succeeds is the "just one more" factor. After your game is up, no other game calls you back for another start like this. Its addictive.
The layout at first glance tells you there is nothing to do. But there is - lots of shots, lots of options of what to go for. The ruleset makes it possible - go for Do or Die or Jericho? Try and master the villians to carry their "lights" over to the next ball?
As far as challenge, i have over 1500 on my HUO, and it still handles me well. BUT - i have learned the table like no other, i have a lot of control of the ball now. This is one game that has made me a better player. Still, the game gets my heart pounding. Only TZ can do that to you when i near LITZ - with IM you get there faster.
Good luck with one and let us know.