There is nothing in the readme stating whether or not to upgrade from 02HA to 02HD. The information only suggests further improvements with 02HD. Therefore, should those of us who installed 02HA successfully install the latest firmware 02HD to get further improvements?
Since there are no drawbacks involved, I'd definitely recommend upgrading to 02HD.
Even though Intel's readme states that you should be aware of possible data loss, I didn't experience any problems when upgrading from 02HA to 02HD (in AHCI mode). All data on the drive were preserved, no SMART errors, everything OK. Just in case there is a "time bomb" issue hidden within the 02HA firmware even with the working drives, I'd assume that it should be safer to upgrade. Obviously, there is something seriously wrong with either the old updater or the old firmware, or both, so without knowing what they actually changed in the 02HD firmware, I'd estimate that an upgrade actually lowers your risk of data loss.
What it all boils down to is communication. They should explain what improvements if any have been made over 02HA and if there is any difference. When you think of it, it is all so simple to do it right and provide the information.