Hey everyone i have a question about this. When I am working on a new model, like a body, and I want to Import a tweaked version of the same body from zbrush (I.E.: Deleted Polygons, or new UVs), i get the pop up about topology has changed, do I want to transfers high res details. and when i say yes, I get my new model with the same subd levels but no sculpted detail.
has this happened to anyone?
To import a mesh into another’s active subdivision level, they must have the exact same vertex count.
If you try to import a mesh with different geometry/vertex count (even as much an single vertex) into another tool’s active subdivision level, undesirable things will happen. Honestly, Im not even sure why Zbrush lets you do it now, it used to be auto-fail.
To transfer detail from one mesh to another mesh with different geometry, you need to append one tool to the other as a subtool, and use the “Project all” function, not the “Import” function. If you must import the second mesh, make sure a non-3d mesh tool is active first. If a 3d tool with subdivision levels is active when you import another mesh, Zbrush thinks you want to “overwrite” the active subD level of that tool.
Hey dude, thanks for that post man… I was working on a new work flow and I don’t like the project all feature, too spiky… i had to mess around with the Projection Distance to get it right.
And it let us do it, because of the preposed GoZ feature in ZB4…
but i am going to try something else…
Well, as a PC user, I have no experience with GoZ…I dont know how it works. It’s possible things may be different now. I had always just assumed it simply automated the projection transfer process onto new geometry.
But traditionally, importing meshes with different geometry directly into another meshes active subdivision level has always been a no-no.
You have to import new geometry on the lowest subdivision level-Zbrush will automatically transfer details 
-it’s one of new features of 3.5 version 
Well i have the exact same problem.
I export my low poly to xsi, scale it to match to the xsi unit, and when I re-import it into zbrush, there no detail.
H-E-L-P