Spendor S8e or Vandersteen 3A-Sig or ?

Since I have owned neither I won't "talk my book" as many do about the system they own. I have heard both, many times and I would choose the Vandy's everytime. Especially with the refined and detailed music you describe listening to, the time and phase coherent nature of the Vandy's will be magical. I do like the Spendors, and they are a more impactful speaker and if you listened to more big orchestral or loud rock music then I would recommend the Spendors.

You will enjoy either of them, so good luck.

I also vote Vandy, but recommend you get rid of the silver I-C and speaker cables.

I would get used S 100s, available for under 3k. New ones, which look to use the same drivers, are approaching 10k. I use them myself.

a coin flip unless you own a cat.

I listened to both and wound up buying the S8es. I'd have to concur with Mlsstl above. The Vandersteens made nice sounds - especially with tubes, but the Spendors were a much tighter more focused sound. They image wonderfully, although they do have a relatively small sweet spot. They also become noticibly more transparent with the grills off. I've had mine for a little over four years now and I'm still very happy with them.