...Back in the day, I never noticed the quality being particularly bad in 1 channel mode (although every extra channel played up to 4 reduces quality as it has to essentially multiplex the channels), and if you REALLY need a modern professional setup then even the 'skyscrapers' (CBX) quality is a bit lower than whats standard fare these days.
So it all depends.. Do you have some fun and dabble, or take time to setup a more professional system?
Dear mate; obviating that we are immersed in a "retro" hobby and that it is currently unnecessary to occupy space with SCSI chains and voluminous hardware complements, I believe that is necessary to remember that the magic is in using our Atari for that, instead of modern devices.
We must also point out that many modern recording systems, with hundreds of plug-ings, infinite possibilities of mastering and a thousand uses integrated in a single program: it is not a guarantee of a good result, at least in what we call "home studio". I have received recordings with a signal-to-noise ratio that seems recorded on a slate disc, and people have modern Cubase with all kinds of compressors, filters and tools for mastering.
Do not underestimate the cleanliness of the CBX with a faithful Atari.
I am delivering audio tracks recorded with the TT and the CBX, and other musicians contribute their tracks recorded with modern systems (Protools, Steinberg, etc); curiously, my "raw" track does not need all the compressors, filters and cleaning that other colleagues need to record acoustic instruments.
Listen to this song (it's not mastered), there are tracks recorded with modern systems and tracks from the old school Atarian, the past and the present coexist:
http://www.mediafire.com/file/8d9g2c3jd ... e.mp3/file
ST/fm/e, STacy, Mega ST/e, TT, Falcon, C-Lab MKX... and more music tools.