More info on rattle #2. Complete description:

After fully, fully warmed up (15 minutes or so; probably 5 minutes after up to full operating temperature) I start getting a nasty rattle. It's in time with the engine rpm. Higher pitch than a rod knock, more of a clack. It comes on slowly, getting louder and louder the longer you drive it. It first begins in the 4500rpm range, but the range gets wider and wider the longer you drive it. It's at it worst when driving a constant speed. A slight amount of throttle makes it stop, as does just letting off the throttle. 20 minutes or so after it starts it's almost constant, doesn't get quiet with throttle trickery. Thinking it might be pre-ignition, I checked the timing (which was on the money), then retarded it a good 10 degrees to be sure it couldn't pre-ignite. No change in rattle so ruled that out (and set timing back to normal). After quite a bit of test driving I found that it only happens with the clutch engaged. Once fully warm and full-time rattle, at any speed and any gear I can push in the clutch and rev the rpms up and down and no rattle that I can detect. I'm now thinking pilot bearing or clutch release bearing for several reasons:

-When clutch is disengaged (no noise) there's no load on the pilot to make it shake, and the throwout bearing is being squeezed, preventing it from rattling.
-It's at it's loudest when maintaining constant speed or very slight deceleration, when the drivetrain is at is lightest load. Enough to start a rattle, but not enough to hold things in place.
-Clutch engaged, lift off of throttle increases the load on the drivetrain, and the noise goes away. Now enough load on the pilot to keep it from rattling.
-Clutch engaged, add throttle also increases the load on the drivetrain, noise goes away. Again, enough load on the pilot to keep it from rattling.
-The noise is in time with engine rpm

I'm not sure which is the more likely culprit--the clutch release bearing or the pilot bearing. Are either (or both) common noise problems with Beats?