The Scandinavian judiciaries in general are far less aggressive about being independent than UK judges are. There's very much an attitude that authorities are more trustworthy that ordinary people in the Scandinavian judiciaries, and a reluctance of the courts to seriously question the police or political decisions.

It's a paradox that the Scandinavian penal systems are far more gentle than the British system (after reforms in the last half a century - they used to be atrocious), and sentences tend to be far shorter, but the police and especially court system are in many respects far more authoritarian, and far more elitist (e.g. Norway is experimenting with more "normal" juries now but is still dominated by a system of "lay judges" picked from a jury pool - I really like the overall system however the jury pool is not regular people as most places, but picked from a pool of candidates nominated by the political parties)

And unlike the UK, which have repeatedly frustrated US authorities by allowing lengthy court proceedings over extraditions, Sweden has kidnapped and black bagged political asylum seekers to illegally hand them over to the CIA, knowing they'd be handed over to the regime they were seeking asylum from.

I'm Norwegian, living in the UK, and I'd be worried about Norwegian courts in a situation like this, but I'd be terrified of Swedish courts if I believed there was a chance of extradition to the US, because in part I'd see it as far less likely I'd get a fair hearing than in the UK, and I'd see it as far more likely that I'd simply get black bagged without the involvement of a court at all.

The big question to me is whether or not Assange genuinely fears that, or if that's been an excuse to avoid going to Sweden.

The longer he's staid in the embassy, the more genuine his fear seems to me - he'd likely have been out if he went to Sweden and was convicted. Unless he'd get extradited. Of course that doesn't need to mean his fear is rational.