The TCD-D5 series had a better transport, with audibly lower flutter than the WM-D6 or -D3, particularly if a tape cassette had higher than normal friction. On the other hand, the later version of the -D6 offered Dolby "C" noise reduction. I never understood why Sony didn't add that to the D5.
When interruptions are expected, patching for multiple recorders needs to be done on a "star" basis--splitting the signal at the source rather than passing it through one recorder into another.
From about 1973 to maybe 1981 I recorded concerts with a Nagra IV-SD + QGB large reel adapter. Even at 3-3/4 ips that deck sounded good. But when the PCM-F1 came out, I bought one from Laox in Tokyo and never looked back. I think that the experience of analog tape recording can be instructive for people who've never done it, but it doesn't offer any overall sonic advantage over digital recording, unless one happens to like a particular type of distortion in a particular situation.