I certainly agree with cutting open, and examining the oil filter. That's a major source of information about the wear occurring in your engine. I can't get quite so excited about oil analysis though. There's nothing wrong with it, but the information it can provide is somewhat limited, as most of the alloys used in the construction of the engine are one of just a few types. Thus the report could come back with a spike of a certain alloy, which could be any one of many parts. As the engine could also contain after market parts, which could be of a different alloy, some of the information reported could be a little decpetive.
I certainly agree with oil analysis for engines which were designed to benefit from this examination technique, as they often contain many different alloys, and the indications in the oil are more descriptive of wear in specific locations.
Certain common defects in these engines are not picked up by oil analysis (sticking valves, sticking piston rings, cracked cylinders, and pulled studs for example).
That said, for a few dollars, oil analysis can't hurt, just don't take it as the final indication of your engine's condition...
Pilot DAR