CD1988,
I have HD ST 3.5 that works for OS 9.2.2. However, while it will work within OS X, one must open it in Classic. In tech has been very slow in upgrading HD ST to OS X. I feel I am stuck since I have 13 partitions while Apple's Drive Setup only allows a max of 9 partitions. Relying on using HD ST within OS 9.2.2 worries me as Apple will probably completely abandon OS 9 in the next 3 - 5 years.
So, if you can live with a Classic version, by all means get HD ST. It will see Drive Setup formatted drives even those within OS X.
MamaMoose