But if your going with such high bitrate on mp3, with no audible difference, (to most people) why not just go full blown lossless.?
It all depends on your situation.
The DAC in the Droid, for example, isn't good enough that lossless will sound any better than a 320 kbps MP3, and the space savings of the MP3s will add up once you get enough files, especially with a relatively small SD card. Same goes for an iPod. And if you're listening in a car, lossless (or even 320 kbps) is mad overkill—road noise, Bluetooth streaming (if you use it), and poor car speakers all take their toll on the sound quality.
In these two situations, the quality advantage of lossless is obliterated, since none of the sound systems involved can reproduce the music accurately enough to make a difference anyway. In this case, the space savings of MP3 are well worth it.
On the other hand, if you're listening at home on good speakers and using a high-quality Firewire DAC (i.e. in a situation where the quality difference IS noticeable), the lossless files are indeed worth the extra hard drive space. I actually keep two copies of most of my music—a set of 256 kbps AACs for portable use and a lossless set for home listening. Obviously it's not worth keeping a lossless copy of, say, spoken word files, or tracks that have been transferred from 78 RPM records. But you haven't lived until you've listened to the Beethoven symphonies in CD quality on a set of studio monitors.