In general, yes. However, the 2010-2012 RX450h SE-L Premier had the option of Active Stabilizers - explained HERE. This came with steel spring suspension. For some reason (cost perhaps?) it seems to have been dropped following the 2012 facelift.
I have this on my car and it is superb, no noticeable body roll in corners whatsoever and a really smooth ride on the straight (when the stabilizers are turned off completely). It doesn't have the ability to lower the car, as the air suspension does, but then there are no leaking bladders to replace. It's also great fun when you connect the car to Techstream and do a test on the stabilizers - the car does a sort of waggle-dance!
I've also attached a list of features across the 2010-2012 RX models.
I hope this is helpful.
David.
Lexus RX Featrures (2010).pdf