I share the same feelings about your 96/24 choice, I tried the highest and in a blind test I couldn't tell one from the other, I needed to read the dap rating to see which one was playing. I have enough to remember what songs are on the player, the sample and bit rates are the least info I pay attention to but my ears do find differences in the different rates to a certain point. The recording quality is a big factor though, the better the best even at lower res. Not that many people consider one importance device in listening tests, our ears. They have limited ability that any technology is not going to improve unless they replace them.
Same here, I re-encoded all my hi-res to 24/44.1 or 24/48 to save space so I can fit my whole library to a 128GB SD card.