The Plextor M3 Pro is on average somewhat faster than the Plextor M3, which makes it one of the fastest or perhaps even the fastest Marvel 88SS9174-based SSDs. The differences are not significant, and the competition is getting pretty tough, especially in terms of pricing. Of course we don't mind paying more for the five-year warranty and the promised reliability. That said, when the Crucial m4 256 GB is available for £180, it is difficult to justify spending another £100 for the Plextor M3 Pro when the advantages aren't that obvious.
Until a new generation of SandForce/Marvell controllers arrives, it is likely that the SSD market will be dominated by a price war the coming months. This is good news for the consumer, but more challenging for brands such as Plextor.