This isn't a VDL question, but since a lot of people here are well tapped in to the world of virtual instruments, I figured it would be a good place to start. Recently, my need for high quality piano samples has greatly increased. The VDL piano is great for Sibelius and making quick recordings, but I'm looking for something that is designed specifically for the piano (I'm a pianist). I've heard good things about Synthogy Ivory and NI's Akoustik Piano, so I'm wondering if anyone here has experience with these samples or has suggestions for other samples that are worth mentioning.
You might also want to check out the East West Quantum Leap Pianos. That is a PLAY instrument (which you can read about on the Sounds Online website) which means you'd be able to deal with a lot more polyphony without taxing your system as much as some libraries. The Pianoteq library also generally gets pretty good reviews from the community.
It will depend on your budget and what you ultimately want out of the instrument: ease of use, realism of feel as well as sound. Some libraries just ";feel"; better to use, especially if you're going to be actually recording tracks, or wanting feedback from the instrument tat is similar to a real piano.
The forum over at Northern Sounds would also be a great place to poke around and ask questions, since that's a community of composers that spans a much wider range that you'll find here. Not to say that we don't have some brilliant minds here, but those people are definitely much more tapped into the rest of the virtual instrument world.