Which form of B12 to take are a hotly debated issue and one that generated quite a bit of internal debate for us as well.
Dr. Michael Greger, at least as recently as 2013, recommends the cyanocobalamin form because there was a greater body of research to support it, and it's cheaper.
However, in 2017 this study came out https://www.ncbi.nlm.nih.gov/pubmed/28223907 which suggested that Methylcobalamin may be easier for the body to use (more bioavailable) than the cyanocobalamin form, which the body must convert. Furthermore, there isn't much of a difference in the price of the two forms anymore.
Regardless, there’s a considerable amount of literature now to support the efficacy of either form, so we don’t actively promote one form over the other, as we think that would be misleading.