At 100K the timing belt, water pump, spark plugs and coils were changed. Recently, the air mix and mode servos for the AC/heat were replaced as well as the bank one sensor one A/F sensor. It's a smooth riding, good car. Sounds like yours has been really good to you.
I have no complaints! Been a Lexus owner since 1991 - several LS, an ES a GS and this RX. This is the least "Lexus" car of them all - ride, noise, smoothness, etc - but, I love its durability (so far!)
As far as maintenance goes, I guess I'll just keep doing what I've been doing: syn oil every 5-6000 miles, antifreeze every couple years, timing belt and water pump and plugs every 100K, trans drain and fill every 20K, differential and transfer case oil change every 60k and every 15k on air filter. I'll look in the book for anything else. I'll search the forum later for strut info.