I don't think a full ensemble strings patch has much use for typical orchestral pieces. It would only be useful when the orchestral piece really directs all strings to play in exact unison. Not so common, AFAIK. If all sections are playing something in sync, they're more likely playing in octaves.
I agree with all that's been said already too. In my own words - Full strings patch reasonable for sketching, or when it's really the sound you're going for. But it will have severe limits for typical orchestral stuff. With individual section patches, you'll be able to emulate that sections are not always accurate with each other, you'll be able to automate each section's xfading parameters independently. Assigning different notes of a chord to different sections will provide a more authentic stereo sound, but even in mono having a properly orchestrated strings chord will have a different sound that is more natural.
I find these "half ensemble" patches in OT libraries very useful - the combinations they provide really are common orchestration tropes - especially the ones where the sections are playing in octaves - so it's nice to just reach for those patches instead of having to program expressive performances on two or three separate tracks. On the other hand, there are plenty of times to need control over individual sections too. So they still don't replace having 5 separate string sections.