You really need to look at VSL. Even the intro packages are awesome. Also EW Hollywood. If you're looking at doing more than "big bam boomy" both VSL and EW have a ton of articulations that some other packages lack.
My humble 2 cents.
I'm totally happy to spend money on good libraries, that is not the primary concern. My fear is that I don't have the technical chops to make them sound good (futz/ massage etc.) and that -in the end- my creativity is going to be hampered by the very technology that's supposed to boost it.
I've considered actually notating the parts in Sibelius and importing the midi into Logic for automation and humanization, but it's still a laborious process.
I'm just afraid libraries like Vienna or EW are going to be "too much" for me to handle all the parameters at once, both the playing aspect and the technical aspect.
Having tried out CineSamples for a few days now here are my findings:
The UI is unified across the samples, which makes them easier to control
The samples are for the most part very realistic sounding out of the box, safe some attack/release issues. I did notice a lot of difference between legato patches and non-legato patches for the same instrument, so those cannot be easily mixed (in a multi-timbral track).
Compared to Spitfire demos, I'm getting that intense, sometimes metallic, always energetic vibe. Maybe like a snowstorm in Minnesota or a sunset in Arizona.
Spitfire gives me the sound of a train ride through the Cotswalds, a dreary seaboard town in Southeast England or maybe a drive with my vintage British motorcycle.
If I'd have to make a choice all over again, I'd have probably gone for the Spitfire Samples first, just cause I'm British and I'm "that kind of guy" who totally digs Walton and that image that the sound conjures. But the next library I'd buy would be CineSamples, just cause my music sounds like Gustav Mahler most of the time and the emotional tension in the strings of CineStrings in the low dynamics is monumental for some of those passages (think Mahler 9th Symphony, first movement, basically every passage).
Nuisances with CineStrings: No divisi and no sordinos, that kills me. Probably gotta run out and buy either Spitfire now or CS2.
I wish I'd never found out about this sample business and stuck with Sibelius and NotePerformer, the amount of money I'm throwing into samples is getting out of hand......