This was just covered in another thread. It was also researched on minidisc.org and discovered to not be true. A fellow there xferred his files and checked the file(s) in Adobe Audition and saw no degradation as has been described. Once again, one test is worth a thousand opinions. Use the RH1 to U/L all your legacy MD's with no fear of having them degraded.
As for saving them as 24 bit; well, if you care to manipulate them on the PC I understand it is a better way to do it, in 24 bit. It will not improve the sound but will add fewer artifacts during manipulation. You will have to resample and dither back to 16 bit.
I seriously wish I could believe this because it would save us all a lot of time. Did you read my posts carefully? http://taperssection.com/index.php/topic,76899.msg1027426.html#msg1027426
I never said SP/LP2 files are being converted to ATRAC3+ as a standard or as an option that I accidentally might have selected (I surely didn't), SS does never inform you about this step, when you convert to WAV your output files are .WAV but they have been converted to ATRAC3+ (no idea on the bitrate) prior to being converted to .WAV, apparently that is the current workaround for the ATRAC-for-the-PC codec as was stated by someone on the German minidisc forum.
This discussion has nothing to do with HiMD recordings, transfers of those are all lossless and no one has claimed otherwise anywhere, just to make this clear once and for all (not saying anyone in this topic did say so, just trying to keep the information as straight as possible in here).
I've done frequency analysis and spectral analysis on files transferred via standalone deck (TOSlink > TOSlink connection) and compared them to the RH1>USB transfers and there were obvious differences, referred to as cut-offs in prior posts, most noticeably on SP recordings, not so bad with LP2 recordings (which all seem to have drop-offs at around 16kHz, as is obvious since the bitrate is really low, 128kbps, I think). You might want to give this a try yourself if you own a deck - I also read some of the minidisc.org discussion and couldn't open the attachment, other than that I just saw someone who "believed" something. Again, try this for yourself and post the results, I'd love to see a new version of SS/the ATRAC codec handle this differently. I'm on 4.2 still afair (am at work right now so can't check).
Shortly after this was being discussed on ts.com the DSEE feature was introduced to SonicStage (coincidence?), it adds something similiar to DSP to the playback of files, thereby making them sound/appear fuller than they were in the first place. So you might get even different results when playing back your .oma in SS and recording the digital output of your soundcard (internal or external) than when doing a straight transfer via USB or via a deck.