Depends on who they let tune it, I suppose. Could be very similar to the mu3 in terms of sig, which isn't exactly a bad thing.
Thanks, friend! I'm a little apprehensive with AKG products since Samsung basically bought the name and outsourced the tuning. The reliable AKG engineers went off to make Austrian Audio, so I don't know how much of the legacy you're going to see in the N400. If they manage to stick to the Harman target and can somehow adjust for loudness properly, I don't see why they wouldn't sound great, though.
Here's the collection as it stands/remains.

85t are still the all-purpose workhorse, surprisingly, though I really wish the tones on their HearID system were just a hair louder. It's really hard to hear most of the tones, but the system overall is pretty effective.
FITS can just be worn practically forever and the DD inside has really matured, helping the low end come out. They're still considerably more neutral than most pairs out there, but it's so good on execution/technicalities.
The Club Pro+ have been the really surprising pair. Their ANC and hearthrough are still pretty weak, but serviceable enough to justify use. They're dead simple to pair up. Wireless charging works flawlessly. EPro tips make these practically perfect for fit and seal.
Unfortunately, the WH3 no longer charges via the USB-C port, but wireless charging does. Think I've gotten one update for the entire lifecycle of the product. Sound sig and lack of support really don't justify the purchase and it seems the WH2 brings more of the same.
We all know about the MTs. I don't have the volume issues anymore. The occasional disconnection still happens, but it's very rare. Still recommend these for the sound signature.
The ADVs are...fine. they'd do the trick if you wanted an aptX pair that was no-fuss, but the mic could really be improved to use as a conference pair. They're very well built, though.
Falcon Pros are still the detail champs of the TWS bunch. The preamp controls finally seem to stick, letting me reliably use aptX adaptive without the artifacting. Using Neutron's AGP really helps.
And the CX400BT? Just fantastic for creating a mood around the music. Can't knock them for that. Still were never worth $200.
The story learned over this journey? Take breaks. You learn way more about your equipment when you just allow yourself to "exist" with it.