Kinda hard to compare since they are so vastly different. The vapor seems quite a bit coolor in the 51, but that is most likely due to the 801 atty with whistle tip as opposed to the 510 that I have on my SB.
Better flavor in the SB too.
But again, I believe the big differences are in the attys (I despise 801s) and probably the power in the different batts.
Better flavor in the SB too.
But again, I believe the big differences are in the attys (I despise 801s) and probably the power in the different batts.