Incase people are not aware Crucial is the retail division of Micron. Micron has now moved the retail drives to the MX series under Crucial and the M series are now moved to the Micron branding. The M550 drives have been replaced with the M600 drives now. I have some on the way and will bench once we get them here. So far reports show promise for the 512GB and 1TB drives. However the smaller capacities are not so promising with the new Dynamic Write Acceleration. Not really a big deal for media since the 256GB drives are normally to small for media. But I likely wouldn't use them for cache either. The far greater endurance on the 512GB and 1TB though looks very promising. Those I look forward to testing especially in raid.
They looked nice but unfortunately not for sale yet. Checked a few times since I first read about them but I couldn't wait forever to order my system. I did however manage to snatch up a few really cheap Plextor M5 Pros so I'm not all too worried about it! hehe