I did a few dumps and each game gives two .isos each with a combined file size of 6.54 GB (7,027,228,672 bytes) which doesn't match the file sizes in the database.
Those dumps are missing the video partitions IIRC.
That's too bad that the Xbox hardware can't do proper dumps (or the available software for it can't) and needs dedicated disc drives.
Kreon models are cheap on ebay.