left handed ratchets are superior to right handed for removing bolts, since it allows you pull instead of push
this means you can exert more power loosening a bolt (since you pull with your dominant hand) then you can tightening a bolt (pulling with your non dominant hand)
so the beauty of a left handed ratchet is that if used properly, you can always undo a bolt you tightened yourself without breaking it
allen wrenches kinda suck no matter what handed ones you use...so generally use allen sockets on a left handed ratchet