Hi Steve,
As you may remember, I have had several pairs of Beolab Penta, Beolab 3000/4500 and my personal favourite Beolab 5000 in my time selling used B&O.
I have listened to your Youtube video comparison of Beolab Penta with Beolab 3000 and feel compelled to report that I was disappointed with the sound quality of the Penta in particular. The bass was overpowering and boomy to the extent that it was almost impossible to listen to the music. The Beolab 3000 sound quality was more acceptable but missing in mid detail.
Personally, i wouldn't buy either of them. Perhaps I was correct, all those years ago, to prefer the Beolab 5000!
By the way, I have gone from 3 pairs of Beolab 5000 with various B&O systems in my 5 bedroom bungalow to Shure SE535 3 way IEM's via Bluetooth to Dell XPS15 in my grannie annexe!!!