I've owned a few Alberts over time (a Buffet, a Conn eefer, a Buescher, to name three) and I still own a Conn hard-rubber Albert that I had restored. I also have a C-Albert (marked Triomphe-Paris) that I had restored. My new Yamaha YCL 457-20 (which I consider to be an Oehler because of the additional intonation-vents and tone-hole rings) was the latest addition to my closet. The intonation is not-so-hot on all of those. The C-Albert may be the best of the bunch.
My Boehms have been much better concerning intonation and as far as tone goes, I don't think anyone could listen to me play all of them and tell me which was a Boehm and which was an Albert/Oehler. Same with two guys I know in SoCal who play Alberts - one a hardcore traditionalist plays an 1887 Buffet and the other - the other more of a swing-style on a newish Hammerschmidt German System. If you didn't see what was being played, you wouldn't know. All in the technique.
The tonal differences alleged to exist among Alberts, Oehlers and Boehms, if there are any at all, are mostly from the player and his/her set-up and not from the horns themselves.
Among my Boehms, the closest to each other in tone are an old R-13 and an RC Prestige - two different horns from different eras, yet they sound very similar - to me from behind the horns. I understand they have different bore designs, too, but I could be wrong about that.
Other Boehms I've owned and played have different tonal qualities (heard only by me, I fear, the audience doesn't know). I attribute this difference to individual horn characteristics, and not to the keywork.
Same with the Alberts I've owned and played. Yes, they were all different, but it was the individual instrument, not the keywork that made them different from each other.
As different as the two basic designs (Boehm and German) may be, I sound like me on all of them. The section lengths are different, the tone-hole placement is different, the tuning barrels are different (56mm on the German, 66mm on the Boehm, and those vary depending on model), but what comes out as I play them sounds amazingly like . . . clarinets.
All one has to do is to listen to the jazz greats who played Alberts (Bechet, Dodds, Noone, Dorsey, Lewis, etc.) to understand that what you are hearing is technique and individualism, not anything to do with the way their horns were designed. DAVE