[daemon13]

In my humble opinion the guy is a great engineer who is bored (by lack of challenging projects) and discouraged (by less than stellar teammates).

It is rather easy to check though - you should forget about time spent on work and need to compare the outcome, i.e. result, of this guy vs every other engineer on the team.

If the check above shows that this guy is better than everybody else, than this:

>> Alarmingly often, he'd have hacker news, or dzone open and would be reading articles (I mean 50%+ of the time, not once or twice a day).

and this:

>> More than one of his coworkers have mentioned something along the lines of "can't we fire him 4 weeks out of 5 ?".

indicates one simple thing - he is not managed properly by his manager and by the company.

It as simple as that...

[gaius]

Agreed. This is a management problem. It is astonishing that here on HN someone could be castigated for spending more time thinking than typing.