I already thought back then that Alvin doing Jimi is rather pointless - it's a forceful power trio version alright, with dynamics and smart musicianly elements too, but there are limits to how much you can wring out of C, G, D, A and E. Alvin's sometimes frantic energy doesn't go too well with the song if you have Jimi's more laconic and laid-back approach in your ear (Jimi sang it like he was in a police questioning and didn't care for his fate further down the road).
Kind of like Rory Gallagher doing "Going Home" - I doubt he could have added too much to it except that he can play a 12-bar fast as well.
Unless I'm severely mistaken the upper bass is a medium or short scale while the lower one is a long scale, they are both fretted.
