I've got both, and it's horses for courses really.
If there's only me, maybe one other to make for, then the Swiss one is so small and lightweight that it wins.
If I'm out for longer than a day's walk, or there are more folks, then the kettle wins hands down.
Enough hot water to wash with as well as a stable base to cook on, and I don't need to lug fuel around either.
Price wise the Swiss one is a bargain, but the KK is just such a useful bit of kit I reckon it's worth every penny I paid for it.
It's so simple that it doesn't need valves, washers, fuel lines, pre-heaters, fuel bottles or specialised tools to keep jets clean, it just works reliably, every time, anywhere I can have a bit of a sit down.
It's the ultimate multi fuel kettle
but no getting away from the bulk of it, though it is easy enough to carry.
cheers,
Toddy