In what scenarios using IPD would you use the C191 contract versus A195, B195, and A295 contracts?

I understand that C191 is considered a “true” contract that is signed by all parties involved (the owner, the architect, and the contractor), whereas the alternative method uses A195 between the owner/contractor, and B195 between the owner and architect, with both A195 and B195 referencing A295.

What I am fuzzy about is how the two different contractual methods impact the responsibility and liability it presents to each party. Can someone give me example scenarios in which the responsibility/liability would play out differently, depending on which contracts were used?

Also, more generally, how do the parties involved decide at the outset which to use?

Thanks!