Well for me, when I talk about a "good" pilot, it definately is in reference to their current level in their career etc... I can say a student pilot is a good pilot, and obviously mean that they are catching on quick, things are pretty natural in the plane, and they don't get cocky. Obviously though they aren't going to be able to perform to commercial or instrument standards(although had one that was pretty damn good once). So for me, it is an open statement, but meant to inspire confidence about someone else.
For a pilot with 500+ hours, being good to me means being smooth. You should know all the basics, now it's time to work on finese'. So that's about all, carry on