Hi, I think it depends on a number of things. Which hotel is it, how important is an upgrade to you, etc.
For what it's worth, upgrading to the Towers at the Sheraton in Hong Kong using points is considered a very good use of points. For one thing, it's impossible as a Gold to be upgraded to the Towers as part of any complimentary upgrade. In order to gain the wisdom from the SPG regs, you'll probably need to be more specific in your desires and locales.
