This is what i do when i have a long stay in Doha:
1. After arriving, I first go through security and into the lounge for dinner/lunch.
2. At around 6-7 pm Doha time i head back to the security check via the elevator and tell the staff there that I want go to arrival. They then assign me a position where I can get back into the transit area through the security control.
3. I go to arrivals and go through immigration. If you have a business class ticket, you can use the arrival lounge there to pass the immigration. There is an immigration counter inside the lounge and usually no queue. You find the lounge very easy if you just turn left after the escalator. When you go back to the airport you can also use the business class desk or if you are first class or business class+Platin QR member you can even use the first class desk which will lead you directly to the Al Sawfa lounge there. This all speeds up the re-entry into the airport.
4. I take the metro to go to my hotel that i have booked at discount price through "Qatar discovery". I prefer now "Crowne Plaza Doha"
Thanks, I will also be staying at the Crowne Plaza Doha - The Business Park', is there a particular exit from Al Doha Jadeda Station'?
The hotel is only 4 metro stations away with the red line from the airport and much cheaper than the Oryx Airport Hotel. From the arrival station "Al Doha Al Jadeda" its is only a 5 min. walk to the hotel.
5. The next morning i book Uber Taxi to the airport which takes maybe 15 minute to the airport. There is usually an Uber in front of the hotel so you dont need to wait for the taxi.
All in all, it's a quick, easy process which takes maybe ~1 hour more time than checking in at the airport hotel but only costs a fraction of what the airport hotel costs. 45$ for a 5 star hotel in doha vs. 360$ for Oryx Airport hotel.