For what it's worth, I have a number of drives that have got tens of thousands of hours of uptime on them in two different fileservers and no errors logged at all. For example, in my media server there are two Samsung HD204UI 2TB drives, one WDC WD20EARX 2TB drive, and two WDC WD30EFRX 3TB drives. Respectively, the raw power on hours values are:

56399
56803
51238
10236
15107

Assuming that these values actually ARE genuinely an hour count, one of those drives has been running for six and a half years continuously.

The other server is has six 1 and 2 TB Samsung drives in it. Last time I checked, a couple of those were over 80000 hours. Since it's in the shed as a semi-offsite backup, and the thing is unheated, it's at times registered drive temperatures according to SMART of -5 degrees or so

The only drive failure I've ever had in that either one was a Seagate drive. In both cases they lasted about a week longer than a year, then died in a matter of hours with creeping bad sector errors until they were totally shot. I was able to recover the data in time, but I haven't bought a Seagate drive since!

I've never had a Samsung drive fail,except for one that was DOA due to incredibly bad packaging from the supplier, and I've got about a dozen of them. None of the Maxtor or WDC drives have failed in the last seven or eight years either.

So it's also possibly just luck, but it's also fairly consistent

On the other hand, I went to a lot of trouble to make sure the drives are kept cool. -5 may be pushing it...