Depends on which model you select I suppose, they are all voiced differently. But except for the late model Sonata which was a 'bit hot' they are fairly balanced with a warm(er) upper-bass midrange. On older model Preludes (or other models) you might want to be careful of ones that have metal tweeters, and you will note that the Prelude Pluses have nothing in common with the earlier Preludes at all. They have also gotten excellent reviews.
A confession first. I was thinking about the Pass 30.5 integrated, not the earlier model. That said, I will also admit that what has kept me back from buying one is that I really do prefer tubes, not just the the good things that they can bring that is hard to get with SS but also the ability to tailor the sound to match speakers and other components in the system by just changing tubes..
I share your priorities, especially after having spent many years chasing the affordable audiophile dream as set forth by the magazines/ reviewers etc without finding anything that really fit. I then stumbled onto the Silverline Bolero's when you could get them at a more reasonable price. And they do it all for me. The have all Dynaudio drivers including Esotar tweeters (which really are a BIG deal). If you have a large room the LaFolia speakers might do well for you and are occasionally available at reasonable prices. They share many of the same drivers with the Boleros but do have back firing woofers that can be a drawback if not considered. Some of the Sonnetina's are also excellent as well. Fortunately there are quite a few reviews and threads on these speakers to help.
At the time I auditioned the Boleros at Silverline's shop I also listened to the small Minuets (stacked) driven by an inexpensive SS amp and unimpressive CD player. I dammed near bought them instead of the Bolero's, they were that good.
FWIW the Silverlines are all designed by Alan Yun, one of the premier speaker designers in the business who, interestingly, is not a slave to some 'industry standard'. He has a really good ear, I think.
Hope that helps a bit. Oh, FWIW, if I were starting over today, I would get the Prelude Pluses and a good integrated tube amp and wait for the rare occasion that a pair of Boleros came up on the used market! :-)
