My question is what situation calls for use of either or?
It's mostly just personal preference but there may be instances where you'd use one over the other such as where your in a tight space and can't really move the connector/cable around enough to solder properly but you can get your crimp tools in there. It can be difficult to solder at the top of a sailboat mast. Crimp tools can be very expensive although for those interested, Mouser sells a decent crimp tool kit
for $79. That's a great deal considering the 5 dies you get with it.