Even as he was alive, Weiss was considered the greatest lute-player and lute-composer of his time. On his tombstone, his friends had Saxon Johann Ulrich von König’s 1720 phrase carved :
"Only Silvius must touch the lute !"

In 1727, his pupil and friend Ernst Gottlieb Baron published his study of the lute. Many passages expose his admiration for his master :

    He was the first to discover things one could do with the lute that had never been conceived until then. And I can sincerely admit that, as for his virtuosity, there is no telling the difference between Mister Weiss and a talented organ-player when it comes to playing fantasies and fugues with his instrument. His arpeggios are of a rare density, his depicting emotions is without comparison, his technique prodigious ; he has an unbelievable delicacy and singing grace. What is more, he is a great improviser and can play, when his fancy commands it, the most beautiful airs, violin concerts even, just by reading the score and realizing the numbered bass phenomenally, whether be it on the lute or on the theorbo. Because Weiss’ art was the only one to draw from that instrument the best, most solid, most gallant and most accomplished music, a great many, inspired by this new method, tried to acquire his skill and talent - much like the Argonauts with the Golden Fleece."

JS Bach’s first biographer, Johann Nickolaus Forkel could not have met Weiss. Yet the study of his suites prompted him, in 1782, to pronounce this significant sentence :

    (They are) written in a frank and robust style and are akin to, for instance, the late JS Bach’s pieces for keyboard instruments."

Forkel had well understood that, like Bach, Weiss believed in JJ Quantz’s theory according to which the « German style » was a « motley style », a successful blending of French and Italian music, which were then dominant.

The meeting between Weiss and JS Bach in Leipzig in 1739 was the occasion for Johann Elias Bach, then JS Bach’s private secretary, to give the following account in a letter addressed to cantor J.W.Koch on the 11th of August of that same year :

    "...We heard some very fine music when Sir my cousin from Dresden [WF Bach], who came to stay for four weeks, together with the two famous lute-players Mister Weiss and Mister Kropffgans [his pupil], gave several performances in our house."

In 1728, when Frederic II visited Berlin upon an invitation of the King of Prussia, margrave Wilhelmine of Bayreuth, a sometime lute-player, payed homage to Weiss in her memoires :

    "To the memory of the famous Weiss, who excels so much in playing the lute that no one has ever matched him and that those who will come after him will only be left with the glory of imitating him"

In a letter to her daughter, Charles VII’s widow wrote that Weiss’ compositions are :

    "infinitely better written, in the style fitting this instrument (...), than all Sezkorn’s [then the lute composer at the court of Munich] screetchings"

David Kellner (see link to Kenneth Sparr's page) was known for his dislike of the lute as a continuous bass instrument. Yet, in his "Loyal Continuous Bass Method", when he wishes to give an example of the difficulty to play the lute, he writes :

    "But that the illustrious Silvius Leopold Weiss can, with his lute, accompany an honest piece and can, with that same instrument, demonstrate what others give up trying to achieve, all that must be attributed to his virtuosity rather than to the instrument."

Luise Gottsched has written two articles, that dealt with Silvius Leopold Weiss, in the "Handlexicon oder Kurzgefaßtes Wörterbuch der schönen Wissenschaften und freyen Künste", that was published by her husband Johann Christoph Gottsched in 1760 (they can be found in complete under Handlexicon). Here only one short excerpt over Silvius' art of playing:

    "His stroke was very gentle; one heard him and didn't know where the tones came from. In phantasizing he was uncompared, piano and forte he had completely in his power. Shortly, he was master of his instrument, and could do with it what he wanted."