If I could choose, I would definitely pick the airside hotel over Oryx Rotana.
Last time I stayed I was too tired to even remember this possibility(?)
It would get me nearly 2 hours of extra sleep.
In other news, the handling of passenger using STPC has improved considerably since the first time I used (about a year ago). Back then all I got was the vouchers from the desk, and then I was on my own.
Last time I had my own personal "assistant" guiding me to the lounge, where there is a dedicated immigration officer handling the immigration process.