I am a fan of the split link. The largest I have knowingly used one on was a 1980's GSXR750. Apart from the FZ8, all of my bikes run a split link.
When I change a chain I tend to go for a heavy duty X ring. I saves having to mess about with adjustment as often. If the chain doesn't come with a split link, I buy one (often 2) separately. I would guess that it is easier, and cheaper, to fit soft links during the manufacturing process.