That is a very nice review. And, it is what I would expect of a very neutral and transparent amplifier. The descriptions and comments in the review also fit my Bel Canto evo amplifier to a "T".
In regards to adding bloom or texture, some tube preamps can soften the sound a bit which may give the impression of adding fullness or texture but, many tube preamps today are very neutral and will not add coloration or artifacts. So one needs to be careful in thinking they can achieve a "fuller" or "more developed" sound character merely by adding a tube preamp. It's not always true.
Remember a typical tube amplifier has slightly different distortion spectrum and, dynamic output impedance than typical solid state amplifiers, switching amps included. The distortion spectra usually includes more even order content than a SS amp which can provide a bit of that perceived "textural" sound. In addition, the higher dynamic output impedance of the tube amplifier will interact with the speaker impedance (especially the complex crossover impedance) and this generally has the effect of providing "bloom" to the midrange. It can be a a pleasing sound character indeed. OTL amplifiers are the extreme example here.
Of course there are tradeoffs on this "bloomy" sound character and, it usually is in the bass area. Woofer cones are generally the speaker elements that need the most damping and, a higher output impedance amplifier is not going to provide the damping that a low output impedance amplifier is. So the result a "looser" bass and less well defined bass character.
My point in this is that a tube preamp may provide some of the desired fullness but, it does not necessarily duplicate the same type sound character that a tube amplifier will provide.
