Those are very different beasts, John. Omnisphere is a synth, and Hollywood Strings is a dedicated strings library. Don't coun't on Omnisphere for bread and butter go-to strings. It won't deliver that. It's mostly great for pop/rock patches to sweeten up a track IMO, and it's not that much a CPU hog, for most patches anyway. I run it easily on my core 2 duo setup.

I did say that layering the strings in Omnisphere can sound great, if you layer them with a dediacted strings library, but don't expect Omnisphere to be a notch up on the strings libraries you already have. It's not. It has about 3-4 layered lush patches, and no solo strings or sections at all. It's a synth, and that it does really well, but not a go-to bread and butter sampler at all. For that NI Kontakt is waaaay ahead of the competition.

I would advice you to take a reincheck on what you really need, John, as these two products are not doing the same things at all...