I didn't see this topic referenced specifically here, so I'll post my experience for others' edification:

If anyone is trying to get reciprocal M Life elite status from their HGP status, I found that the web link to 'opt-in' at www.hyatt.com/mlife would always stall on me (continues loading indefinitely with no actions taken). A call to Hyatt support using a number on the same webpage was extremely unhelpful--the rep repeated 'the website isn't working' (something I already knew) and just to try again later.

A quick call to M Life Member Services at 866.761.7111, however, along with the provision of some basic account info yielded me gold status in about 10 minutes flat ^^