the mini is cool..good loking and character.. about the paintjob.. you have the same light in all teh mini..you should consider that if the light comes from the top..as it use to do (cenital source light) the upper parts shoud have more light than the bottom parts.. then, if you achieve more contrast the overall efect will be better in all teh mini.. the clue is to contrst all with very very fine lines to underline and highlighht and that is the way to separate the volumes.. but it should be so fine..and never with blac or white.. use colours near to the palette taht you are using.
the conversion is nice. but about the composition it could be better if you break the frontal wiev and move some parts like the head, arms, etc.. it is usually better when the movement of the head and maybe arms goes in another direction of the body..it is a question of composition.. normally the better wievs are when the body and head are not in the same plane.. the same comparing with the base..
sorry for my bad english and of course those are my opinions and advices, so please dont take it in a wrong way. ;) .. thanks for your comment and keep on your work. best regards from spain