the good side of burst is that you can use every hdd/ssd you have, even with realocated or bad blocks or ready to fail ( smart problem ) disks
as long as you can read from it, it generate Burst with no penalty
the other 2 you need to run over raid1 ( mirror ) if you don't want to lose money
with 18Tb on Burst for 1 mounth I have 17000 bursts
you can do the math with currect price
It's kind of pointless to me to halve your disk space on the off chance that a drive might fail.
And you can use multiple smaller drives in Storj with whatever size you want so if a drive fails not everything is ruined.