Known problems with Momentus XT
Despite the hype some people have serious problems with these drives, just check out the Seagate forum where they've started a Google spreadsheet for customers to record their problems. e.g. loud noises and system freezing. My Windows 7 desktop locks up randomly because the drive is choking for some reason. I bought 4 of the damn drives 3 months ago thinking I was making a money saving trade-off to get extra capacity than a real SSD but is still faster than a normal mechanical drive (for booting or loading favourite apps).
I've now bought a 120GB SSD to replace the Momentus boot drive and my desktop is working properly now - and soooooo much faster. I was not at all impressed with the performance of the Momentus. In my personal experience the real world performance of this hyprid is hype. I realise a lot of people are very happy with theirs but the firmware is still buggy for those who get unlucky.