Maybe not the 2nd best, but he's easily up there in the top 10. Massively underrated imo.
Superb kicking game, excellent distribution (often overlooked), surprisingly robust defense (his storming defensive display vs SA in November comes to mind) and arguably one of, if not the, best 10s under high ball playing international rugby. Mercurial goal kicker to boot too.
His running game isn't as good as the likes of Sexton, but he's no slouch (try vs France for example). Most importantly, he can keep a cool head and control a game. Something missing from a lot of Welsh 10's in recent years.
Again, to reiterate, not no.2 in the world, but he comfortably rubs shoulders with the best - But hey, just my opinion I guess!