I prefer 320 myself. I also find it to be a little clearer and sharper even on low end gear. I can notice a more distinct difference when I wear my headphones which are a much higher quality.
It can also depend on the music itself and how it was recorded. Ie you would notice a difference between classical and techno.
Either way, 192 would be the minimum rate I'd personally use. I'm not fussed about space saving.