I read Ken's article. Almost sounds as if he's on the apple payroll.
First, bit rate (and bit depth) matter very much but it will only matter as it relates to what you are listening through. Stock buds, most docks, and almost all car stereos will sounds fine at 256 maybe even 128 all though I do not know why you would not use 320. The space issue is not that significant to today's world of terabyte drives. As we know, once you take down the rate unless you keep the original source it's gone.
There is little question that a perfect LP sounds better than most CD's light years better than a compressed digital a file. I could never live with LP's. Digital is just way more convenient. There are several reasons LP's sound great. The one most objective one is an LP can be converted to a bit depth of double a cd and a bit rate of 96000! Cd's brought this down to 14411 and you can read about how this was decided. There was some sound logic used to decide this. Taking the bit rate down further seems to be strictly a function of cost and marketing choices. It most certainly affects the quality for those who choose to invest in equipment that make 14411 and higher bit rate sound glorious. Ken mentions several well known music components that used with additional equipment (like a headphone amp, or separate DACs) would with out question decipher between a 128 and 14411 file. I don't know....a quality headphone without quality amplification plugged directly into IPOD...maybe you can't hear a appreciable difference.
The point hear is 256 is fine for many people, probably most. If you love great sound and invested some money to hear it 128 is unacceptable. 256 pretty unacceptable. I've listened and compared and the following I know is subjective but here goes....listening through a good headphone system...and mine is mostest by many standards say about a total spend of $2500, you can identify a 128 file 100% of the time. At 320 not quite as easy. If the production of the recording is stellar it could fool you. Decipher it from a 14411 file can be made 90% of time. I can not decipher between 14411 and 96000 but at 192000 you can decipher nearly 100% of the time against a 14411 file. Having a IPOD Classic which has plenty of space, every thing gets reduced to 320 for car listening. I likely would not notice 256 files. My problem is even though there are places to buy high resolution files, selection is limited. For final word, apple try as you might there are many formats like flac you ignore and it makes me thing less of Apple for doing this.
Larry