I am currently selling a Rowland Concerto integrated so take what I say here with a grain of salt. I have not listened to the Simaudio nor the Tylers but I am very familiar with the Rowland. First and foremost the Rowland in my system is exceptionally neutral, no mid-bass warmth, no exaggerated bass and no tilted up highs, although it does lack a bit of air or space compared to my previous integrated a McIntosh 2275 tubed integrated. My speakers are JM Lab Mini Utopias which I would also classify as neutral albeit with limited bass extension.
I don't want to put words in his mouth but I think what Bobgates is referring to when he says "refined" is that the neutrality leads to a totally grain free, edge free sound. It's not tube like, it's not typical solid state like. Detail is very good but you're not getting artificial tilted-up highs for more perceived detail at the expense of listener fatigue. In fact, when I first listened to the Rowland in my system there were two things I noticed about the sound: 1. With my limited bass speakers I missed the mid-bass warmth of the Mac. I felt the "coloration" of the Mac made for a better match with my speakers. 2. Detail and dynamics were so good I was halfway expecting listener fatigue, but it just doesn't happen. Although I will say that when I used Kimber Silver Streak balanced interconnect from my Ayre CX-7e CD player to the Rowland it made for a bright sound. Not fatiguing but just not to my liking. Switching to Cardas Golden Cross and ultimately Synergistic Research Luminescence solved that problem.
Due to its neutrality and clarity my recommendation is to mate this integrated with a speaker that doesn't need a boost in the midbass. A more full range speaker with deeper bass extension to take advantage of the full frequency range of the Rowland would probably be best. If you are looking for a very expansive sound with a lot of ambience stick with tubes. In my limited experience with tubes they do that very, very well (although you may run into problems with limited dynamics and a softer bass for tubes in this price range). Also, the Rowland is very sensitive to cables, more so than any other component I have used. I tried a total of 5 or 6 different cables with audible differences with each.
Keep in mind too that my comments are based on comparisons with equipment that are $4,000 to $5,000 used (integrated or amp/preamp combinations). I'm sure there are more expensive components that offer better resolution, clarity (although its clarity may be hard to beat at any price), more space, more sophistication but I haven't heard it at this price point. If you are looking for neutrality, dynamics and clarity it's hard to beat.
