I'm looking to get my first SSD. I'm after a 120/128 GB model. It looks like a simple choice between the Crucial M4 and the OCZ Vertex 3 but my question is this... I only have a Sata II interface so if I were buy a cheaper drive, would I get the same performance? Alternatively would it be worth spending an extra however-much for a 6gb/s controller card (I'm not willing to upgrade my whole system to accommodate a new motherboard). If so can someone recommend one at a reasonable price?