I wouldn't say belt drive designs are bad, I've owned and enjoyed several during my decades in this hobby.
But I do find good DD and rim drive designs to be more accurate and musically satisfying. The most obvious example came from a friend recently when he installed a Teres rim drive to replace the belt system on his VPI Scout. Some would consider this an unusual modification since the Teres cost as much as the Scout table and arm package. However, just a couple of minutes listening to a solo piano recording revealed the significantly improved accuracy and musicality which far better resembled a live piano. Other instruments and voices benefitted as well but the piano provided an easy and immediate comparison.
Specifically to the OP's question, I agree with everything that Sonofjim said about DDs as it was a better summary of points I was suggesting in my previous post.
But I do find good DD and rim drive designs to be more accurate and musically satisfying. The most obvious example came from a friend recently when he installed a Teres rim drive to replace the belt system on his VPI Scout. Some would consider this an unusual modification since the Teres cost as much as the Scout table and arm package. However, just a couple of minutes listening to a solo piano recording revealed the significantly improved accuracy and musicality which far better resembled a live piano. Other instruments and voices benefitted as well but the piano provided an easy and immediate comparison.
Specifically to the OP's question, I agree with everything that Sonofjim said about DDs as it was a better summary of points I was suggesting in my previous post.