I just measured and reviewed my blue
here (external link) with comparisons to the EMU Teak, but I don't have the regular version. The measurement rig I use is also different from ie. Crinacle or Oratory's. The anniversary tuning seems to have fuller mids and less bass boost. But I'd really need to measure the OG to be sure.
My biggest takeaway from pad rolling is that the EMU pads or similarly the Accessory House Denon pads make the TH900 a lot easier to listen to. Mids are much fuller and smoother. In stock form I still enjoy it but it is really track dependent - classical, jazz, and accoustic music sound brilliant but poorly mastered rock or metal can be overbearing. The biggest difference between EMU pads and Accessories House pads is that the latter further reduces the upper treble peak at around 11-12khz, so that is recommended if you find the treble too sparkly.
The TH900MK2 SB is pretty much my end game closed back. You can choose between two types of tuning with pad rolling, and there's also the option of swaping to different wood chambers offered by EMU and Lawton Audio. There's endless potential to this headphone.