> DOSLFN is small enough and reliable to be constantly loaded as TSR.
It's not bug-free though - it seems to have problems in its SFN handling. Many times I've seen the Borland Pascal IDE complain about not being able to create a SFN file when DOSLFN 4.x is active, but BP7 works perfectly without DOSLFN and also in a Win9x DOS box.
The other big problem with an LFN DOS is that (to my knowedge) there is no equivalent to the Win9x version of ScanDisk, which means that any file system corruption cannot fixed if there are any LFN's on that volume.