Being a bit of a string purist, I would agree with Boydie - although I would say considering this instrument is a synth and not a sample, it's surprisingly good. If you're after a cheap sample the NI Session Strings are good value for money too. I've used them on a couple of demos, but when I was pitching to publishers, they picked up on the 'unrealistic' quality of my strings (their words), so I upgraded to EW Hollywood Strings. Quite expensive, but a big difference. The problem for me is, the more closely you listen, the less real they all sound, especially if you spend a lot of time listening to real strings.
I do think there's an art to making any sampled strings sound more realistic in your song mix - usually it's about writing convincing parts, and using the right reverbs. I'm still a noob to be honest, but it's a lot of fun learning it