my mp-01 suffers from chipped paint on the die cast parts and one of his leg pops off. also the front chest doors dont line up properly, but nothing major. however ive banned myself from transforming him ever again to avoid more chipped paint and loose limbs.
i too am tempted to get the mp-04 from robot kingdom but only because i am collecting the whole MP series. otherwise i would be happy with just the 20th anniversary edition. even the dvd edition is a steal for such a great toy.