Some initial notes on setup and sound:
VTL amps - first thing I wanted to try was backing on off on the feedback - the MB450s have an adjustable local feedback setting (the amps have no global feedback) allowing 4 settings ranging from low to high. With my VR44 passives, I had to set this to medium-high - the second highest setting - as the amps were driving the woofers as well as the MT unit.
With the VR55 aktives, I found that I could dial back the feedback all the way to the lowest setting - this provides the best sonic performance and this is evidenced by the huge, open, and airy soundstage these amps put out at this setting. This is a big win sonically speaking, and I found the pairing of the MB450s with the VR55s to be exceptional - of course I'm a bit biased

For those of you not familiar with VTL amps and Luke Manley's work, I encourage you to read the reviews on the MB450 MKIII amps - they are not your father's tube amp

The amps can also be switched on the fly between tetrode and triode mode - my preference with the VR44s was the tetrode setting and that remains true with the VR55s though the sonic impact of triode mode is less so with the VR55s. In short, triode mode does sweeten the sound and makes for a more relaxed presentation but at the cost of a more confined soundstage, more muted dynamics (relatively speaking), and less air around the instruments.
Now on to the speakers and the sound!
The speakers have about 400 hours of break-in at the factory so they are over what I call the "ugly duckling" phase

Overall the speakers are still running a bit hot and forward in their presentation (think first row seating) - Albert says they will mellow with more time (another 100-200 hours) so I'll see how this changes as I put more hours on them. This was also the case when I went to demo a pair at Albert's facility - though mine are further along compared to what I remember hearing there.
If I had to use one word to describe these speakers, it would be "organic" - as in natural, effortless, and achieving a level of coherency that makes the music flow with an ease and balance that few speakers I've heard have achieved. I recently auditioned a pair of Q5s paired with VTL Siegfried amps and the VR55s sound better in every way other than perhaps achieving the ultimate degree of resolution. This I attribute mostly to my amps as the Siegfrieds will outperform the MB450s in that regard. The Q5s by comparison sounded analytical, and lacked the ability to convey the emotional overtones of the music and frankly left me cold and unimpressed.
This is of course my own personal opinion - I know many folks who thought the Q5s sounded amazing but that is not the sound I am going after - just a personal preference.
On to some details - all of these notes are based on vinyl as the source as that is my listening preference, and without any changes to the setup during the listening session other than where noted.
I started with a bit of a torture test - Emerson Lake & Palmer's title album - the organ is huge on this album and can bring many systems to their knees. I especially like the track "Take a Pebble" and here the VR55s were exceptional in their articulation of the piano solo in the middle of the track, each note distinct, clear, and precisely located in the soundstage. The timbre and harmonic structure of the piano was spot on and even in the most demanding of passages, the VR55s never even hinted at compromising their composure. Dynamics - you bet - there in spades when needed but never over-emphasized or unnaturally aggressive - just a natural reproduction of the music as recorded - nothing more, nothing less.
Next up, Dark Side of the Moon - I have a german pressing of this album that is amazing - trounces every re-issue I've ever heard (and I have them all), vinyl or digital. I played the first side all the way through as once I dropped the needle on the first track, I was sucked in for the duration

The VR55s did not disappoint here either - the clocks at the opening of Time were reproduced with such clarity and spatial resolution that it felt like I was standing in the middle of the shoppe where they were recorded. At the end of the chimes, there is one grandfather clock still sounding and you could hear the woody cabinet resonance, as well as the transient decay and rich harmonic structure of the chimes with a clarity I've never experienced before (yes, you will hear me repeat this many times

). The soundstage throughout was huge, open, and three dimensional - the VR44s also exhibit a great, wide soundstage but not as deep as the VR55s - nor are they as open and airy.
I have to say, the VR55s convey an amazing sense of space and openness with this recording. You feel enveloped by the sound, to the point of being part of the soundstage rather than being presented with a soundstage in front of your listening position - if you get my meaning.
Next up is Fleetwood Mac - Need Your Love So Bad from The Pious Bird of Good Omen - a great recording with very sweet and natural sound and great vocals by Peter Green and Christie McVie.
On this song, Peter Green's vocals are front and center and the VR55s deliver such an emotionally compelling presentation that it was difficult not to get totally immersed and forget about note taking and paying attention to the "sound". A bit clichéd you might say, but isn't that the goal of all our efforts in sound reproduction - to forget about all the equipment and just be taken along by the music?

Well the VR55s do this better than any speaker in my (albeit limited) experience.
The sound here is rich, smooth, and sweet - but not in an artificial way - you simply hear what is on the vinyl.
There's more but I should wrap up here for now as my wife is giving me hints I've been on the computer too long

- if you don't get that I'm extremely please with these speakers, you must have dozed off while reading this

The VR55s disappear like no other speaker I've heard - they simply get out of the way of the music and present such a natural and uncolored sound that you quickly forget you are listening to a reproduction. They let you fall into the music and convey the emotional landscape of the recording in an immediately tangible and believable way - and isn't that the point of listening to music?
I'll keep adding to my notes as my experience with these speakers grows and as they continue to break in.
Well done Albert - you've outdone yourself with these speakers!