My only hotel experience on Century is the Radisson. Good and bad, but it's all about expectations.
First, GREAT views of the Southern complex and supposedly good viewing of arrivals on the North (only ever had a South facing room). Sadly, they have a very, very annoying film covering the windows, I think to prevent heat/glare. It really even messes up spotting with the naked eye, let alone photography, but it's still do-able I guess.
Second, the Radisson's roof-top bar was still closed to the general public as of last August (last time I was there). I have snuck up there before and the view is GREAT. This is unfortunate, as it's a super-prime location.
Overall, if you're in SoCal you ought to be OUTSIDE not hold-up in your hotel room. Just saying. It's a 5 minute walk to In N Out.
Having explored the Parking Spot, I would have to bear you this warning. It's not spotter-friendly AT ALL. They have signs posted all over prohibitting photography and loitering. Furthermore, they have cameras all over, and people staffing a central "office" at the bottom so you will be seen and asked to leave most likely.