This is probably the hardest metal kit I have done so far. But when it was done I have to it is the most fulfilling.
It's a MU model that's available from Jolly Whale and is an officially licensed product from Hasbro.
Its 8 sheets to steel and a 9 star difficulty rating. (I’m not sure how hard is the hardest, but I think it would be 10) The package claims its takes over 22 estimated hours to finish.
I did this over the course of a couple of weeks, so I'm not sure how long it took me.
All i know is there was A LOT of metal bending and juggling to hold pieces in places while other pieces were bent to secure them.
Some of the pieces were stupidly small, but helped give this model a fantastic level of detail.
I had to learn many new holding techniques that i wouldn't normally have used for the metal earth models.
Those little round rubber things aren't what you think they are. They unroll on your fingers to help provide better grip and to help prevent the metal edges from slicing your fingers.
With an instruction manual this think, i knew i was in for the Long Haul.
The first piece next to MP 10G Optimus Prime for size comparison.