I only use midi clips for drums so it's not a big problem.
Got it set now so preview goes to Steven Slate drums plat, before I found out how, I'd pick a midi clip and it'd play back trough my guitar library wrecking havoc with the key switches.
Every time I make a pattern, say a hihat or ride pattern that I spent some time on getting
just right, I drag it to the browser to my clip library so I can grab it again when doing a similar drum track and get a groove going fast.
Just wish I could figure out why Sonar has to create a 5 second delay the first time I drag a clip from the browser, it's just a midi clip so it shouldn't cause that large a lag, and clips doesn't do this when previewing in the browser. After dragging it in, and the initial delay, it plays back instantly.
I had a similar problem back in X1 with the metronome, toggling it caused a 5 second delay for some reason, that was fixed in X2.