The specific version, the S-300 PT, was the original version. It uses the antiquated Tin Shield surviellance radar, Flap Lid fire control system, and often a Clam Shell low altitude radar. The PT version is of limited mobility, and reloads are often prevented by the hot launch damaging the TEL. The SA-10 missile is NOT a long-range system. Belarus has been replacing it's S-300 PT and S-300V systems with the PS model. The claim by Iran is for an obsolete version not the S-300 PMU which Russia was to have delivered. US and Israeli pilots have been training against the much more capable S-300 PMU in Red Flag exercises for years. Perspective folks. This is not a game changing development.
Singapore arrests man who tried to join ISIS (Reuters)
from the article: Iran official: We have obtained the S-300 missile system