I agree that via bt it lacks a bit of bass punch and treble, and is a bit flat sounding. But everything is pretty much fixed if you use a good warm mid and bass centric amp like a fiio. Though that does defeat the purpose of having bt. Needless to say I moved on to something else, when I realised I was paying 50 bucks for bt, which I have no use for.
 
Honestly akg products tend to need  external amps to sound amazing, even though some of their headphones shouldn't need one at all.

Well, although I compared so many BT Headphones lately, I am not a Pro Head-Fier. This is probably the difference between us, I would have never thought about an Amp because I never used one in my life. But you are of course right, at least at home people could use this headphone with a good amp.
Although even when I am at home, once I start getting used to the freedom of BT, I just can't use cables anymore.
But in each decision there is apparently always some pros and some cons.
 
Considering your good tastes I am not curious about what you have now, after dismissing the AKG.