Look at a speaker as a whole. Think about how you will integrate them into your room. Speakers can sound hot, tiresome and shrill for many reasons and tweeter is just one potential culprit. Inadequate amplification that can’t get the bass right, room acoustics with untreated walls and floors and associated equipment are all going to be more influential than the material the tweeter is made from, at least in the case of Wilson speakers.
Don’t overthink it when it comes to the tweeter
For recordings to use, try Diana Krall “Peel Me a Grape” - good test to see how sibilant the speaker is. It’s also a good track to test the bass.
Keb Mo “I Was Wrong” is a busy track that’s recorded extremely well and is good to test soundstage and how realistic the cymbals sound.