safex is supposed to be one a privacy-based token set that uses a decentralized marketplace much like silk road (although it has been promised to launch year after year for 3 years without having anything), Safex Platinum is a privacy-focused lending blockchain in which users can take loans out that repay themselves thru locking staking rewards until the loans are repaid. they both share similar attributes by being cryptonote based and have 2 tokens on one blockchain. other than that there's not much similarity.
safex has 1.8 billion tokens block times of 2 mins
safex platinum 21 million block times of 90 sec

that's just the technical differences in the projects