There's no show-stoppers here - just some handy properties that used to be in the OCX but no longer are:
IsReady (actually TestUnitReady)
IsBlank
IsWritable
IsErasable
Also, the following would be handy:
IsLoaded
IsCD
IsDvd
IsHDDvd
IsBluRay
Almost all of this can be handled through enums and bitwise operators, so it's no biggie at all. If you were ever bored and looking for something quick but handy, this might be it.
I wrap it all with my own interfaces any how to make it easy to compare StarBurn against competitor SDKs on a level playing field and to leave me free to mix and match. StarBurn is the best I've found any how (I even prefer it way over Nero's SDK and I do like Nero as a product).
This great forum you have here and your sane licencing scheme are big bonuses.