I updated dashboard to 2.0.13604.0 and finished RGH. Before RGH DVD was probably flashed with iXtreme LT+ v1.91 or 1.92.
You ran system update with ixtreme on the drive already and it didn't break with errors during update?
No, it never does. Slim has 0225 16D4S which never gets updated. So it doesn't matter if its iXtreme or not.