While both products are of pharmaceutical grade quality, and do not differ in the look or taste, it is the manufacturing process where the difference lies.
There are two methods of manufacture, crystallization and distillation. MiSMo's regular MSM is produced by the crystallization method which is done by centrifuge (fast spinning).
The manufacturing process used for Distilled MSM is more involved and results in a super purified product which is the reason for the higher cost. Described simply, Distilled MSM is a process where steam is captured thereby ensuring the most purified crystals possible.
MiSMo Distilled MSM goes through a 4 stage distillation process to achieve maximum purity. The water content of the Distilled MSM is below 0.1% which is indicative of very high quality and is 99.97% pure.
The water filtration is also a point of difference for MiSMo MSM. All water used in the manufacture of MiSMo MSM has been treated by the Reverse osmosis process.
It is universally accepted that Distilled MSM is the absolute purest form of MSM available.