bump to be in thread, I am considering purchasing izotope SOON for cassette transfers; and might I add Ben Turnbull has been helpful to me in realizing this is the product for me. which module, as is, would be recommended for analog to digi transfers?
You can apply a pretty good amount of de-noise to tape. Use it within RX7 instead of as a plug in, and select the highest quality render (D?). Do it in multiple passes if needed, I'll typically do an overall light pass, then possibly a second pass for specific noisy regions, which could be spots in time or an overall frequency range.
Related but different from music work, I have used de-noise with spoken word content in a room with an air conditioner running full blast, reduced it to a low hiss with two passes of roughly -12 for different aspects of the noise. Room sounds silent. Previously the AC was extremely distracting and masked some low level speech. The voices sound somewhat different, there is a penalty, but they don't have obvious artifacts. A person not familiar with the raw audio would not think it sounded off.