Thanks for your answer. The hours indeed do not match at all our schedule
Earlier, I was also looking into using the UA's Arrival Lounge (w/ showers). I am not sure, if we would have had access though:
see here
There also
an old thread with mixed lounge-access experiences to the KrisFlyer lounge.
Thanks again for your help. I am still very happy with the Hyatt option, since it offers a bed, a TV and a breakfast buffet
I'll report how it was...
/ xanth
Edit: back from the trip - Even though the day-rate officially starts at 10am, we were given a room at 6h30am and left at 5pm. Everything worked out fine. Would do it again this way.