I recently wrote a report on my experiences with my Serac in another thread. I'll just copy and paste here, with minor editing:
Before buying the Galibier, I had an Acoustic Solid "Classic Wood," with the Acoustic Solid WBT211, which is very similar to the Jelco-based Artisan, and an upgrade from the Rega RB250 sold with that tt.
The Acoustic Solid is a fine turntable, but there's no comparison with the Galibier: the Serac (with the Artisan as well as the Tri-planar) has more extension, greater dynamic range, much better layering and provides quieter, deeper background. As a result, the sound is a more "solid" in all aspects. I had a Zyx Airy 3 on the Acoustic Solid, and now have this same cartridge on the Serac.
I first heard the Serac with the Artisan arm at Thom's place in April. I auditioned it with the Serac platter and the Gavia platter; I also heard the Gavia base/platter/motor pod combo with the Tri-Planar arm (although with different cartridges: Serac with the Universe, Gavia with the Dynavector XV-1s). One thing that struck me as common among all those permutations was the quality of the background and the remarkably solid layering. Moving from Serac to Gavia platter increased the amount of detail and the differentiation between instruments in space, which is alreday remarkable with the Serac. Going to the full Gavia combo made that even more striking, although the Dynavector is so different than the Universe that I wasn't so sure who was doing what at that point (and most of my listening time was on the Serac). I didn't hear the Serac with the Tri-planar at Thom's but since that's the arm I got with my Serac, I can vouch for a great match. The Serac is really worth that great arm.
One last thing that I find particularly attractive in the case of the Galibier tts, is that one can move up incrementally to the higher models: start with a Serac base with Serac platter, then move up to Gavia platter or Gavia base (note that nobody is quite sure yet which part is best to upgrade first, the base or the platter--I know what Thom used to recommend but he's going to do some more testing), Stelvio amrboard, etc. The process is very easy and is well documented on the Galibier site--you can also see what parts are similar in all models. So you spend ca.$4000 today, get great sound, and sometime later can end up with a top-flight analog rig.
And, as mentioned above, it's such a treat to work with Thom!
As you can see, I find nothing "romantic or mellow" to the sound of the Galibiers I've heard. In fact, they're more on the side of neutral than mellow, to my ears.