OK - Not Great - be weary of fees!
NOTE: THERE ARE NO WORKOUT FACILITIES AT THIS LOCATION.
The Hyatt website talk about all of these great amenities, but the workout facility is not a part of Hayatt and costs $20 PER PERSON PER DAY. HUGE disappointment to pay this kind of money and have to pay an additional $20 per person for the Equinox club which is just "ok." The machines are kind of old, the free-weights are limited, it's a very cramped gym - but the treadmills, stairmasters, etc. are very nice.
The good: It's clean and the staff is friendly. You're only a 15 minute walk to Rodeo Drive (it'll cost $11 to take a cab to Wilshire/Rodeo - only 1.3 miles away - very expensive for a short trip). Many fun places to walk to within 5 minutes and a lot of really good restaurants close by as well...do some research on google maps or Yelp - don't rely on the concierge.
The bad: Additional cost for the workout facility, the food is OK at best - thus overpriced as well. The pool does not have enough "lounge" seating for how large this facility is. Get a seat by 10AM or you'll likely be sitting on a grassy area. 
The "free" wifi in the lobby is VERY slow if more than 5 people are using it.
The valet is totally not worth it - it's like watching the keystone cops trying to get cars, cabs, limos through - we wound up waiting FOREVER to get a car or a cab every day.
If your company sends you here on business - you won't be miserable. I would not recommend coming to this facility for personal/pleasure reasons. Again, very clean and quiet rooms, but the food and drinks are overpriced for what it is and there are not free amenities - you have to pay for everything.
Also - be weary of the desk clerks. We took advantage of their "pay $100 for $150" of hotel amenities and I'm still trying to help the front desk understand how they overcharged us.