I know this has been asked 1.7 million times before, probably even by me, but it should be something Cakewalk takes note of because it's just not intuitive, so I'm asking again. They should make this important functionality much clearer.
 
OK, my piano sound has been the ones that came with my Yamaha P-105 keyboard, and that's been okay for a few years. But I want some more flexibility, so I purchased Waves Grand Rhapsody which is a collection of good piano sounds with some more options. But now, there's a nearly imperceptible delay between pressing a key and the sound. It's so tiny that you can't hear it, but when playing the instrument, my pianist brain can tell something's not right. 
 
So, I know there are some preferences I can fiddle with involving buffers and latency settings and whatnot, but (and here's where Cakewalk should make it a lot clearer) I've never really understood those settings, something about buffers. There's one for playback and one for recording, and there are some sorts of trade-offs in terms of latency vs dropouts, depending on your RAM and whatever else.
 
I know many of you reading this know exactly what I'm talking about. I've randomly messed with numbers in preferences, but nothing has made a difference, so I'm not finding it. Help?

In your settings, try lowering your ASIO sample rate for recording to as low as it will go without getting dropouts.  I find 256 to be a good starting point.

What you're experiencing is normal latency caused by the amount of time it takes your computer to process sound. Unfortunately, it makes fast-attack instruments such as pianos and drums difficult to play. If you think pianos are bad, try a harpsichord!
 
You can reduce latency by lowering your audio buffer size, but unless you have a very powerful computer and aren't using any effects, some delay will always be there and it'll continue to annoy you, especially playing fast parts.
 
As a piano player myself who likes to play fast, let me offer you a solution. Play your parts on the Yamaha, but do not record its audio. Instead, record its MIDI output. After you've captured your performance, direct that MIDI track to the sample library of your choice. Then you'll get the best of both worlds: real-time monitoring and the higher-quality sounds from deeply-sampled libraries.