Claim: Like other common iron-based catalysts, PEPPSI is not stable when exposed to air and moisture, and overheating it results in decomposition.
Evidence: In comparison to many alternative palladium catalysts, PEPPSI-type complexes are stable to air and moisture and are relatively easy to synthesize and handle. 
Contrary to common palladium-based catalysts, such as tetrakis(triphenylphosphine)palladium(0), PEPPSI is stable to exposure to air and moisture.