-193dbFS??? Don't print that over on Gearslutz, you'll start an argument over whether or not that's audible!

Total rubbish Freddie. You think you can hear the difference between 44.1 and 48 because you know when the two different sampling rates are being used. In a controlled A/B test you would not have a hope. Period! Been there, done the test on some very good ears, better than yours my friend, they all failed miserably.

I agree about 24 bit, that is important. 44.1K / 24 bit is fine especially if you are going to end up on a CD. (dithering down to 16 bit of course during final stage of mastering) One less stage of down sampling to consider. 48K is good for music that is ultimately going to be involved in DVD or TV productions etc because they tend to use that sampling rate. One less stage of upsampling required.

When the music is that good Freddie sampling rate does not come into it. People who go on with this sort of rubbish are usually dealing with sub standard music and are looking for other reasons why it is that way. They are looking to the tools instead of other much more important things.

Many quality plugins are upsampling and doing their thing sure at higher sampling rates. That is important not the difference between 44.1 and 48 though, that is not so important.

(Please note I have blind A/B switched the finest turntable on the planet with pickup, RIAA equaliser and finest vinyl against the same signal going through a 44.1K 16 Bit bottle neck and still no one picked it. The analog setup would be equivalent to very very high sampling rates and high bit depths)

96 Khz compared to 44.1 Khz I could understand for sure but not 48 to 44.1 KHz though. That is rubbish. No professional I have ever known or read has said the difference between 44.1 and 48 is night and day. Not enough difference there to make such a rash statement. End of story. What the OP was about was 48 compared to 44.1. The reasons are due to the music ending up in a different media, not sound quality.

96 compared to 44.1 is another story. Although many great people have also said that it is also unnecessary. 

NOTE: A to D converters can sound different at different sampling rates. Higher sampling rates do NOT necessarily mean better sound. One brand of converter and design can easily sound better at 44.1 compared to the same converter running at 96K. Fact. And that brand sounding great at 44.1 can sound BETTER than another converter running at 96K.

That is the real truth. The reason why a studio may be running at 96K is because its converters sound better at that sampling rate. Main reason. And they should do it if that is the case.

Higher sampling rates means your plugins are all working harder too and you are dealing with larger amounts of data. In a controlled A/B experiment I bet many people would have great difficulty hearing the difference between 44.1/16 Bit and 96K/24 Bit anyway.

Seriously Freddie, if it's really "night and day", why do so many users go onto forums to ask which one they should use?