Listened on headphones through my PC. The Joni Mitchell "Willy" sounded fine to me.
Zeppelin's "Battle" sounded normal. Sibilance is present, but natural. FWIW, I compared yours with the Amazon's "Ultra HD" version and found sibilance present there as well, (maybe a bit more), but again, natural. If I had to nitpick, I'd say it sounds like the treble was mixed a little hot, but not overly so.
In all fairness, my headphones are cheapies and don't do either of these recordings justice. My 2¢ opinion(guess?) - You may be sensitive to sibilance, but these 2 tracks, esp. "Battle", would probably have anyone with borderline sensitivity grimacing. I wouldn't declare them as benchmarks for concern.