Alright, so after a few days of listening, here's what I found. First of all, at first listen, I was shocked how much lower the volume is vs the Sonys. it's almost like 50% lower. But it turns out there's a strange flaw, hopefully fixable by firmware, where if you take one earpiece out and the case closes before you take the other one out, the overall volume is cut in half, which makes it so that even at max volume, it's too low.
The other thing is that the Pass-through function also has a flaw. If it's enabled when you take the PI7s out of the case, bass levels is boosted way up and treble way down. You'd have to turn off Pass-through and noise cancellation from the app to make it sound normal. I think if you just turn off the pass-through before you put it back in the case, it doesn't do this.
Thankfully, I found a workaround to these two things because I was so ready to return it. Hopefully I won't run into anymore problems.
Now, compared to the Sonys, wow! The PI7 makes the Sonys sound congested, especially in the midbass. The bass on the PI7 is pretty strong, a bit too strong with certain modern music at times, but it sounds tight and pretty good textured. More like a really good IEM than your typical TWS. It is surprisingly agile, too. There's no boominess, no flabby sound, just good strong bass on the stock earbud. I tried the Final Audio which I had on the Sonys, and that made the bass way too overpowering, so the stocks are fine for me.
The mids are pretty nice, although I sometimes can use a bit more mid-treble, but by no means is it recessed. It has really good body and timbre as well as imaging. It's not too forward or too intimate.
The treble and mid-treble I think is where the PI7 really shines. The addition of a BA means even with a strong solid bass, the treble and higher part of the melody remains clear and distinct. I wouldn't say it's airy, but it's crisp and pronounced with really good separation and timbre. Most importantly, it never gets harsh or fatiguing.
Soundstage and imaging is really good as well, and I'd say the PI7 is closer to my LCD-3 than any other TWS I've owned. I've own the Noble Audio Falcon which kinda has a weird frequency response to me and always sound lacking a bit, and while the Sony XM3 does keep up w/ the timbre and tonality, the PI7 beats it every other aspect, ESPECIALLY fit!
I've always had problems with the XM3 and even the Noble Audio Falco. Both fall out my ear, with the XM3 being the worst at this. If I'm eating and even talking, the XM3 has a tendency of falling out, and if I listen to music in bed and I lay my head to one side the XM3 would fall out. This is not so with the PI7. The way you rotate it backwards secures the PI7 very tightly. I've eaten with it, I've shaken my head, and I've even listened to music with one side on my pillow. In all cases, the PI7 does not budge.
So yes, there are some quirks with volume and pass-through, which I hope Bowers and Wilkin will fix in future firmware, but this TWS is as audiophile-grade as I've listened.
Oh, it makes pretty good Zoom and phone calls, too. Once in a while, the other person on Zoom may asked me to repeated a few words again, but for the most part, they can hear me clearly.