Hi David,
I had done Perth on two ocassions previously, when my husband was still alive, our daughter lives in Perth but always wanted to see more of the country....so glad I took the step, and it was a big step I can tell you!!
Go for it - I did Novemebr last year - just loved it, espically Ayres Rock & Alice Springs!!
Enjoy, you will be so glad you did....I know I am!