I'm not sure how directly this will answer your question or if you've already made up your mind, but I hope it helps.
I used the Apple Extended Keyboard II back in the '90s, and was thrilled when Matias came out with the original Tactile Pro (Tactile Pro 1?) back around 2003 or so. I then discovered how much louder it was than my AEK II. I kept it hoping I would adjust, but I never did. It sat unused. In the interest of full disclosure it should be noted that I have NO experience with its subsequent revisions (Tactile Pro 2/3/4) so I can't say if the newer ones would have been more to my liking.
I can tell you two things:
1. Had the QuietPro existed back then, I would have bought it in a heartbeat, and I intend to buy one as soon as I can.
2. Though I was not a fan of the original Tactile Pro's sound compared to my AEK II, I was (and am still today) a huge fan of the build quality, and the feel of the keys. In those respects, it soundly trounced any keyboard Apple has released this century. In my opinion, the gap has widened (in Matias' favor) with each new keyboard Apple has released.
While I have no hands-on experience with the Quiet Pro (yet), I would say with zero hesitation, if you want a keyboard that comes closest to the AEK II, get a QuietPro. That's what I intend to do, and I won't look back.
Disclaimer: No affiliation with Matias, just a mighty impressed customer.