oh and for live the tone isnt gonna change that mcuh, the room your playing in affects the tone WAY more than a live in case. im a professional musician and am on the road more than half of the year, so the protection is a must.
When micing the cab there is practically no difference.
In e.g. rehearsal room there is sort of a increased bass response and woofy effect. It's not that drastic, but still audible. Also, according to my experience the volume levels have rather significant impact to the matter as well.