I do agree that to evaluate speakers, one must hear for one's self. Still, in the hope that it will help you, here is my impression of the Valentina P8. I imagine the A8 is similar, if somewhat better in David Janszen's telling.
If someone wants to hear what is on each recording, reproduced with even frequency response, great dynamics, and low distortion, the Valentinas will do it. If the listener wants all recordings to sound similar -- say, warm and comfortable -- the Valentinas probably are not for them.
As to involvement: with a reasonably good recording, I can become quite deeply involved in music when listening through the Valentinas. It's hard to compare to other speakers I've owned (including Apogees, Revels, NHTs, Thiels, and others), as I owned them in different houses, with different systems, and my own age and experience were different. However, none of them was better than the Valentinas at involvement. The Thiels were tough -- too bright for me -- and the Apogees were fun but tended to make all recordings sound big and juicy.
If you don't want to know when a recording has natural ambiance and when it has fake ambiance, the Valentinas are not for you.
One strong point of the Janszens is reduced interaction with the room, compared to cone speakers or dipoles. I like that -- it's a tremendous asset in my low-ceilinged, somewhat narrow, room. Other listeners prefer a lot of room interaction, which to some makes a more agreeable "soundstage." The Janszens can come with side tweeters to mimic that a bit, but the presentation is still different from most cone speakers. You will hear more of the ambiance on the recording, and less what your room adds. At least that's my impression (and that expressed in Robert E Greene's review in TAS), but I should note that my room is acoustically treated, which influences what I hear.
Another strong point is that the tonal balance is adjustable through toe-in (as with many speakers), and also through the woofer and tweeter controls, which most speakers lack these days. That's in the P versions. The A versions have additional adjustments, I believe.
I hope that that helps. Still, and especially if you've not owned electrostatics before, I'd recommend a home trial before ruling them in or out. They are really special speakers -- in a good way. As others have said, people like different flavors, and that's as true of speakers as ice cream.