Thomas Cleary was indeed a prolific
translator and produced many popular books.
Sadly, I must say that I have read the originals and have translated some of the same works that he had translated and I cannot recommend them at all. Passages that were difficult were often skipped over without mention of the ellipsis. Passages that were ambiguous and require deep study and comparative reading were given a cursory interpretation. As well, his translation of terms such as "myo" (in Japanese, "ming" in Chinese) which means "bright, dawning, wonderous, insight, acumen" and so on as "mystic" I find disturbing in its distortions. Thomas Cleary was infamous amidst scholars of Buddhist Studies and I have read many an unkind review published in the various university journals. To a certain extent I believe the tone to sometimes be due to envy of his popularity but the specific criticisms have always been valid.
His brother, Christopher Cleary, has always taken much greater care in his translations and has produced only a fraction of the body of work that Thomas had; however they are of much greater and more lasting value.