I think Hyatt has relatively few spectacular lounges. A big part of the problem is that Hyatt's footprint in the region of the world where the best lounges are found (Asia) is very limited. Those Hyatts that do exist here generally have decent lounges, but I can't think of a single location where Hyatt is clearly ahead of the competition. Even the ones generally accepted here as "standouts" -- e.g., GH HK and KL -- aren't quite as good as the competition (e.g., IC HK and LM KL). And there are many Asian Hyatt lounges that are just so-so, like HR Tokyo, GH Fukuoka, HR Osaka, GH Bali, HR Danang, HR Hua Hin, HR TST, HR Sha Tin, etc.