Great Invasion CB is useful for chunking out blobs while their backs are turned, but its easy to exploit.
The border disputes are a welcome if expensive respite for counts or dukes who are realm-locked under a king. Like most Christians. Its not useful for most kings, and too expensive to spam if you aren't a king.
Holy Wars and crusades remain my primary means of land-gaining en masse. And taking land from powerful vassals who succeed in these. But, I will say that I'm a fan of the new 'duchy-tier' de jure wars.
I haven't used the 'tributary states' CB much, because its usually worth more to just murder and absorb the target kingdom. But every once in a while I do demand tribute from some marginally profitable count or duke in some land I don't actively want. Tribute states would probably be more useful for a tribal who wanted to stay tribal or a nomad or some such poor-economy lord. Or for RP purposes.
Force vassalization is, again, something more useful for people who don't have access to an easier CB. Why force them to capitulate when you could more likely claim their land outright, or holy war it?
P: Also, if tributary wars would cost no threat gain or not trigger defensive pacts, I might be more inclined to use them. Actually, I'm making that an official suggestion.