Known Bugs and Issues

The random subobject selection doesn't correctly support the starting conditions (all/selected/not selected subobjects), if you detach/delete subobjects during the sequence. This is because the topology changes during the sequence. It would be possible to track these changes, but this is intricate and I haven't implemented yet.
Note that this tool was written for LOW poly work and thus isn't very optimized. Performing some mesh AK's options on a mesh with 80000 Polys will take a long time. Some functions are unuseable slow on big meshes; especially poly mapping. Don't even think about mapping a 80000 faces polygon...
But this doesn't come true for all parts of Mesh AK. Especially the paint modes are highly optimized (of course, as these are useful in high poly work). Just try it out, if it suits your needs.
VertPaint is not completely finished. Some features, like alpha, are still missing. Additionally, in the final version VertPaint should have a face/poly/element mode, to paint these subobjects.
Sculpt is not completely finished too. Especially the subobject modes a modifier below on the stack are not regarded.
Sometimes target weld doesn't work at all, when snap to vertex is activated. This may look as if the uv correction didn't work – but in fact the vertices are not welded at all. This is a bug in max – it happens too, if you discard MeshAK and try the same in Editable Mesh. I'll try to find the reason for this and create a workaround.
In some cases the object properties buttons don't behave correctly. E.g. you switch see-through to on, but you don't see any change. Or you switch it off, and the object seems to dissappear from the viewport. This is not a Mesh AK problem; the same things happen in the original object properties dialog. Instead, it is a driver issue if you use the Direct X driver. Go to max' driver configuration page, and switch "Use Cached D3DXMeshes" to "off" to fix this.
Sometimes, an "Attach" and "Attach List" is not undoable. In other cases, it is undoable, but mapping errors occur, if you redo. This is not Mesh AK specific; Edit/Editable Mesh show exactly the same misbehaviour. Will hopefully be fixed in the future.
The implementation of the retriangulation after slicing is not very impressive. It's slow (at least it's much faster, as if you had to fix all these unwanted edge splits manually ;-) and the angle of the newly created faces is not regarded, which sometimes results in very unfavourable (long and spikey) faces. It sometimes might need some work turnig edges afterwards, especially on concave faces.