Can you hear bit rate?

I also noticed that the higher the sample rate the more processing power is required. By a fair amount. Supposedly this creates more noise. To be honest, I couldn't hear any benifit of up-sampling so I just backed away from it. 

Depends what you are doing with it, but sure if you are upsampling and doing parametric EQ then that will take more CPU time.  It does seem to affect the heat generated by a DAC though.  That is, higher sampling rates seem to create more heat and sometimes more stability issues.  Another reason I avoid anything higher than 192k.  

This is very true!! I think this happens less with most recordings being digital first, but when they used to make CD's from analog masters, each pressing could be digitally remastered.  This would explain for instance, DSOTM sounding so different depending on the pressing, despite all being digital. 

Paul McGowen. He said in order to get the most out of high res DSD the original recording MUST be done using DSD throughout. To take a standard resolution and then up-sample to DSD would not yield a better result.

DSD is a very weird duck.  Because of the way digitization happens it was very hard for instance to apply digital EQ to the recording afterwards.  This made a lot of things difficult to try to keep clean.  PCM however lends itself to EQ very nicely, allowing you to EQ track by track. 

If you had DSD and wanted to EQ it, you'd have to either convert to PCM, or convert to analog, EQ, and then return to DSD, not really a very good process overall for purity. 

BTW, (unpaid plug for friends) have you guys checked out Blue Coast Records? 

Anthony H. Cordesman, late reviewer for TAS, wrote the following. I agree with it completely, which is why I kept a copy:

When it comes to actual recordings, I have not yet heard any reason to even go as high as 192kHz. Some of my colleagues disagree, but I have so far found rates above 96kHz/24 bits to be a waste of money. I do buy the 96kHz/24-bit version of the music I download or stream for safety’s sake, but most of the time, a good 16-bit/44.1kHz version of the same mastering of a recordings will sound exactly the same. One has to be very careful in paying what usually is nearly twice as much for the 96kHz/24-bit when there is no way to hear whether there is any difference, particularly with a modern DAC with really good filtering. Oddly enough, the better your DAC, the less likely you are to hear any difference.

Original text here.

My two cents is that I'm much more interested the care and aesthetic choices made during the recording, mixing and mastering process than I am in the file storage format chosen for consumer distribution.  I have some stunningly beautiful recordings done in 44.1K/16 while I've heard some very so-so recordings done in 96K/24 or 192K/24.  Put another way, for me, music first, recording quality second, file storage format last.