Drubin: With respect to digitization, you may be thinking of taped concerts, like the Detroit Symphony concerts and others (which I'm assuming are digitally taped). Quite frankly, I can live with that to hear live performances of top-notch orchestras. But I believe the WQXR studio broadcasts are a direct feed from the mike! They certainly sound much more visceral, to the point that you can recognize them easily even over a car radio. On smaller ensembles with chamber pieces, these live broadcasts can sound stunningly real on a good tuner. The NYPO live broadcasts vary--unfortunately they often make the soloists in a concerto sound far larger than life, but the full orchestra pieces sound quite good, until the compression sets in on the major climaxes. The Met broadcasts are excellent, to the point that I often listen to them even though I'm not a big opera fan; you can follow the performers around the stage, hear the footsteps, etc.--very close to being there in some respects. Maybe I'll yet learn to appreciate opera through these broadcasts.
The frequency range on FM cuts off below 35 hz, I believe, and above 15khz, but I can hear very little above 12khz these days and 35hz gives you very good bass extension (if your tuner is a good one, it will do a very good job reproducing those notes), if not the last octave. More than enough to give a good illusion and convey the music well.
The one fly in the ointment against buying a top tuner I see is the impending onset of digital broadcasting. Who knows when it will start to replace what we have, if at all, and what it will mean for traditional FM broadcasts. I imagine there will still be a large number of FM stations anyway, as not all can afford to re-equip to do digital broadcasting. Maybe a tuner can be adjusted by the manufacturer to receive, if not decode, the digital broaadcast signal. And I've been wondering about this for a lot of years, so maybe there's still a lot more time till digital takes hold. But while I guess it is something to keep in the back of your mind, I don't think it necessarily should keep you from maximizing your enjoyment of what comes free over the airwaves now.