I am getting conflicting answers to this question. Ifixit site makes a clear distinction (to include cost differential) between these 2 options. However, web research and other Sites suggest that there is no physical nor electrical difference (just an Apple part number distinction) between any of the mid 2010 to late 2014 PS units. I have a late 2014 Mini PS that I want to keep as a spare for a mid 2010 Mini. Definitive technical answer as to physical and electrical (to include connector pin-out) compatibility would be appreciated!