Here is the link to the photo shots of M4 http://artzone.daz3d.com/index.php?mode=photo_album&p_id=138 This link worked for me and I don't think you need to be an artzone member to see them.  Now keep in mind that this is not an "official" Daz release.  These shots are just some that someone had in their gallery.  You cannot see any bending, just the model in the "zeroed" pose.

From what I can see he is much more muscular, more manly. Sort of like M2 but better detailed.
From what I can see in the shot that shows the wireframe over the rest,they have moved the polygons around a little, made them a bit more evenly distributed, but have not added much if any. This is much the same as they have done with V4, and I expect that alot of the same "improvements" that went into V4 will be included in M4.  I like the look of this model much more than M3 and if it bends at least as well as V4 then it will be an improvement.  However, there is only so much that can be done with the geometry of the current model, and this cannot really be changed or else they would have to scrap all former support products, nothing would fit the new geometry.  Basically you would have to start all over.

I would say, if you liked V4, then you will probably like M4.

P.S. People are coming by the critique forum to my post of my model expecting to see M4, not that I mind, but my model is not M4, its a completely new model.  I think earlier in this thread
the person who directed traffic to my model was not saying this is M4. He was saying hey! before you decide on M4 take a look at this guy's model, and so the confusion.

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A HOMELAND FOR POSER FINALLY