mars marsled led reflector mars2 marsii

First time grower. I'm currently in a 4x2 tent using two old Mars 300's for 3 plants. I want to get an additional tent 4x4 or 5x5 and buy additional led's. I'd like to use the old Mars 300's in the 4x2 for clone and/or early vegging. My question is what is the difference with the Mars 2 vs...