Guys, with BC ships, set the units to generic and scale to meters (tools tab on the right panel> measure to get a readout). I've always been scaling BC ships like this, and it is precise enough (I use the scale rightclick window and scale with keyboard inputs, not the mouse, again this is a precision matter).
Centurus, Baz: with the 3ds>mod>nif stuff you'll have a lot of problems on the mesh (mostly because mod format will always kill the smoothing to a single group, the format doesn't allow for more than a single group. This is why ppl always split meshes to elements by smoothing group before exporting to mod), either always port directly to mod or nif. You have a script called back from five (Google it), which lets you import meshes to older versions of max (doesn't export from Max2009 on, maybe the author updated it, I haven't checked for a long time).