So my valve cover gasket started leaking in the back and I decided to tackle all the "while you're in there" jobs. Specifically: Beisan seals and bearings, DISA repair and new spark plugs. The cars feel different for sure, the power dip a bit more pronounced but I think it's because the torque around the dip has actually increased. By the way the DISA valve was completely toast at 80K miles. None of the parts separated but the center core wore enough that the flap was freely moving, completely unrelated to the motion of the solenoid.

There was a snag as always... somebody doesn't like to read instructions... guess which bolt snapped as a result of being a left hand thread

In any case, smooth drive, no rattle and hopefully no smell of burnt oil, which I'll know for sure tomorrow.

cheers!