Also very similar to Linehill. Bought my 56 reg from local Lexus shop at 60,000, now 81,000. Only problem was air bag on passenger side - they replaced the seat under warranty, allegedly at a cost to them of £4000!
I get 27mpg winter, 32 summer on a 70 miles round trip commute - but I do enjoy using the full power of the 3.3 V6 from time to time! It's on a service plan at £33/month. Add on about £600 every 15,000 miles or so for tyres.
I've had better handling cars, but it's not too stressful on motorways and no-one buys an RX for the corners!
I agree that its snow handling is surprisingly good - I wasted £150 on snow chains which I've never needed.
The interior trim is not exactly luxurious and I've had the odd rattle, but that is exaggerated by the quietness of the ride. The older ICE systems are a bit of an afterthought - poor quality box bolted underneath the driver's seat. We currently can't get any sound from ours. The Mark Levinson audio on the other hand is excellent, especially when parked up (but keep the Ready light on or you'll have a flat battery!). There can't be many less intuitive sat-navs.
Also, the paint job is not too robust, as mentioned elsewhere in these forums. Be careful not to get too close to hedgerows in the countryside, or rub bags against it getting in and out, as marks which would polish out on a BMW are a bit more permanent on the RX.
Having said all that, I look forward to many more years of trouble-free commuting and if the mpg doesn't put you off, would recommend it.