Sun/Oracle LTO Drives are just HP or IBM Drives with modified Firmware.
We have plenty of them in use, only differnce is we have them attached to FibreChannel.
Probably we don't get what you really search for.
If you think your Tapes weren't written to full capacity you probably don't have to worry. DataProtector writes the Tapes full all the way before exchanging for a new one.
Exception are newer Drives like T10'000C with more then 4TB capacity, that Bug probably will fall with DP9.02.
Where to find the Capacity written to tape after Hardwarecompression was already well described by Bob