All drives have a certain percentage of failures and the more a drive sells, the number of reported failures will also increase correspondingly. Unless in a rare case where there IS a specific problem with a drive, where you'd have an extremely large number.
I kinda like the wd passport, it's really portable compared to the rest, not very sure about the goflex because i've only used the expansion, which is HUGE. only problem with the passport is it's a scratch, fingerprint and dust magnet. If fitting comfy in a shirt pocket isn't a priority, the elements is a good option, less of a 'magnet'.
I'm not sure the goflex has a dock, it's just a cable with a large attachment.
This is a pic of a goflex turbo, but you get the idea. i may be wrong of course, there are dozens of variants these days.
For performance benchmarks, google would be your best bet, i'm sure people out there keep doing comparative reviews of portable hdds.