The big problem is
that W98 and earlier cannot read it at all
It is true that there is no native MS support for NTFS in the Win9x family: however, there are 3rd party add-ins that allow NTFS partitions to be read by Win9x OS's.
With the advent of FAT32, the 2Gig barrier was finally broken and
sensible sized clusters could be used
True - but only up to 32GB - after that, the block size is 32K
< = 512MB --512 Bytes
< = 8GB ---- 4 Kilobytes
< = 16GB --- 8 Kilobytes
< = 32GB --- 16 Kilobytes
> = 32GB --- 32 Kilobytes
Compare this to NTFS - block size is a constant 4KB by default (can be increased from 0.5 KB to 64 kB depending on the application).
Note that If you setup Windows on FAT and then convert the volume from FAT to NTFS, it usually causes Master File Table (MFT) fragmentation, so in general, converted partitions are somewhat slower than ones originally created as NTFS. The only solution to this is to backup everything, re-format and restore.
SD