I've had 'Voyager' status for a couple of years. Mostly stay at Langham Place in HK and Langham in Auckland.

Pretty reliably get an upgrade every couple of visits and have never had a bad room. Particularly in HK they appear to want to give an upgrade (Auckland not so much).

Other benefits are free internet, late check-out (to 6pm), 2 welcome amenities (I pick wine and choc usually - you can choose what you want), complimentary international newspaper (in addition to local paper) + the usual stuff (luggage tags etc).