AtmaSphere Upgrade from Mk 3.1 to Mk 3.3

I have a pair of MA-1 Silver Anniversary edition amps that I had upgraded to Mk 3.1 some time ago.  I see they are now up to Mk 3.III.  Has anyone made this upgrade?  What did you hear different, and how significant was it?

The update causes blacker backgrounds with a smoother and more detailed presentation. The new Constant Current Source (CCS) has nearly 2 orders of magnitude greater performance- and results in greater differential effect in the voltage amplifier. All the updates from the Mk3.2 level are included in the Mk3.3 level; the Mk3.2 has measurably lower IM distortion, which is audible as smoother sound.
Well, I did it, upgraded my Silver Series from 3.1 to 3.3  Having the amps back for a while now, I can say I'm very impressed with the results, and that the upgrade gave me a significant helping of the sound I was looking for. The sound after update is much more open and dynamic. I'm quite shocked at the difference. I thought the amps were pretty good already. The increase in dynamics seems to be due to a reduction in noise floor, rather than an increase in peaks, if that makes sense. Sounds seem to stop more completely, leaving tiny gaps between notes, rather than blurring them together.  The same is true of complex passages, where different instrumental lines can be heard more distinctly from each other.  The system is more satisfying when played at low volumes now. Bass also seems more controlled and tighter. The overall impression is that the music sounds more powerful and vivid across the spectrum. More detail can be heard from the very deepest bass through the highest frequencies, but without being fatiguing. I did notice an increase in high-frequency extension, which I was surprised at. In my case it worked out well. My speakers have a switch to help match the speakers to the amplifiers. I had it set in the position that boosts highs a bit. Since the update, ti sounds more natural with the switch in the normal position, and now sounds better than before with the switch in the other position. The increased resolution is not a result of simply boosting the highs, but is a real improvement across the board.
@honest1 ,
I am glad you posted your experience. I am also glad that you found it a significant upgrade.
BTW, did you get the Caddock Resistor upgrade?
Thanks for that info.
I really wish I had done it while it was in the shop.
Oh well, something to add to my upgrade list...