I imagine all these changes are to keep it current into is last year of production. The HL and RX are based on the Camry/ES platform which has been redone for 2007, I would imagine both these SUVs will be revamped in mid to late 2007.
We have an 05 HL and cross shopped the RX. Basically, we bought the HL because we didn't want to Lexus' in the driveway (what would the neighbours think) and we saved about $3,000 and got a sunroof. However, the first time I took it in for service and was treated like the owner of a '88 Corolla, while my Lexus bretheren were given ES loaners and chilled water in the waiting room I wished I spent the diference.
Personally I love the stalk cruise switch, its totally intuitive, tap up to increase speed, down to coast and pull forward to turn off. It is a design stollen from Mercedes in the 80s. In terms of the knob, I couldn't tell you.