Answer:
In my opinion, it is very reliable! My friend has had hers for a year and a half now without a case on it. I, on the other hand, have had mine for only 3 months and in a case, and both of ours are working great. The only thing about it that makes me nervous is that it has a hard drive in it, which could break on a high impact. Although, I've dropped mine 4 times on the school bus, twice on a hard floor, 3 times on the carpet, and 1 time on the treadmill, causing it to hit the treadmill at 4 feet high and go into the wall behind. Even though it was in a clear hard case the whole time, it still works great! Also, my friend dropped hers 20 feet out of her window (it fell on accident) and it still works great with just a small dent on the top corner! If you purchase one, I recommend getting a simple case for it, to both protect the shiny back from scratches, and keep it working.