I haven't undertaken any recent recordings with the Denon DRR-730 but with pop or jazz music often it's worth skipping the Dolby encoding. However, classical music generally has a wide dynamic range so Dolby is important.
Interestingly, I found in my collection three four-decade-old audiophile cassettes, the Advent CR/70 series. These were recorded on relatively slow (four times speed) tape duplicators using BASF chromium dioxide tape, excellent electronics, 70-uSec EQ and Dolby-B. Those tape titles sound quite good given their age, though one of them does exhibit a few dropouts. One contains four Haydn symphonies played by a chamber orchestra, "The Little Orchestra of London", and the performances are sprightly and the audio refreshingly ambient and realistic. Another contains music of Kurt Weill in the original woodwind jazz band scoring, while a third is a sensual reading of the Rachmaninoff Third Symphony (recorded by the now-defunct Delos Records) with the National Philharmonic conducted by Leopold Stokowski.
Somewhere in my boxes I also have three Mobile Fidelity audiophile cassettes from the early 1980s: Earl Klugh's Finger Paintings, Strauss' Also Sprach Zarathustra (Reiner/Chicago Symphony/1962) and Respighi tone poems (Cleveland Orchestra/Maazel). I recall those sounded good, but last time I auditioned these it seemed like the high frequency content had rolled off quite a bit and I needed to switch from the 70 uSec EQ specified by Mobile Fidelity to standard 120 uSec EQ, and they still didn't sound quite as vivid as my past recollections. By contrast, those early 1970s Advent tapes sounded pretty good other than the cassette shell design seemed to be good but not state-of-the-art.