Spendor D Series sounds nothing like traditional Spendor, which has a reputation of being very laid back.
If you like traditional Spendor, you probably will not like D Series. In my case, D Series is perfect, because of the LPZ (in-house made by Spendor). It is quick and lively, not bright (in my opinion.
I listened to 20+ speakers. Bright (or at least brighter, everyone will hear differently) tweeters are Klipsch, Focal, Paradigm, B&W, and others. Not Spendor D series. They are neutral, BUT COMPARED to traditional Spendor, yes, they sound brighter. But that is because traditional Spendor is probably in the lower 30% of all speakers re brightness.
It’s all in the perspective.
I own D7, D1, and SA1. Listen to each every day. IMO, D series destroys the SA1, but as we say, it is all personal preference. Go and listen. Stores mostly open now.