Lexus are fine automobiles, you will probably be much happier with one. My brother has two RX 300s and he thinks they are great.

When he was looking I recommended them over the ML since he does not maintain his own vehicles and pays someone to do same.

One of them did need to have a valve job because it was burning so much oil. Fortunately it was done under warranty about 3K miles before the warranty was set to expire.

It's to bad Mercedes are not as good a quality as Lexus, my opinion, but that's the way it is.