Let me start by saying that I am not a typical computer user - we buy lots of hard drives for data imaging and analysis - we thrash hard drives to death and buy a lot of internal hard drives each month.
We regularly use portable hard drives for on-site work, connect them and thrash them constantly for hours on end. We've been through dozens of different makes and models before we found these Toshiba drives. They are great - extremely fast compared to other 2.5" drives with USB interfaces, and so far we haven't had a bad one. We currently have about thirty of these drives, and all work absolutely fine - as long as Toshiba keep manufacturing them, these are the only portable drives we will buy.
Sure, I know portable hard drives aren't the most sexy product on the market, but if you need reliable portable storage, these are the drives to get.