The trouble, you can't really look at conviction rates apart from sentencing and prosecution rates. And all that still doesn't catch the cultural differences for not reporting this kind of a very personal crime. (This has been evident in Finland among immigrant communities. Not just afraid to talk per se, socially, but afraid of the judicial machinery too. I've sort of been there as a supporter for a witness, on a strong standing, and still the cold bureaucratic process with its uncertainties scared the hell out of me.)
I mostly agree with you. I'm not sure you have Sweden's stats right, you didn't say where you drew them from.
In our neighboring Finland, things seem to be average, and it's mostly a similar system as the other Nordics have. (Not by imitation but by first hand experience. This is reflected in education -- weird countries like Vietnam are now importing the knowhow so it has become an export product worth something. I don't know but some others are thinking we're doing it right, in this area. They don't even know we're going to fall down in the PISA scores soon, for good reason. [A positive reason. Not sure you're interested in this edu stuff.])
You can't really say "the US" is a nightmare when it's all about the States and their own legislation and practises. How about 50 different readings any day. Okay it's a legit nightmare from a lawyer viewpoint, grant you that.