Cross posted from the "what did you do today" thread, but if you're like me, you don't read those long threads, and this would be interesting information to me.
Replaced valve cover and spark plug sealing gaskets. I had 1 spark plug hole on each bank filling with oil.
I have always done 10K mile oil changes and didn't find a spec of sludge after 210K miles.
I just found a write up of the same job for the original 1GR-FE in the 4th gen. Interesting comparison of the differences in the head design for the cam bearings, exhaust side VVTi, and the difference in sludge. This engine had only 116K miles. Also, they put in an additional oil passage running through the valve cover spraying oil from the top, which probably is a lot of the difference between my spotless valve cover and the 4th with cooked on oil.