Stayed here earlier this week and fully agree with the positive review.
Public transport is an option,
Having arrived at terminal 2, I took the free airport bus to terminal 4. From the arrivals level €2 and three stops on bus 827 took me to Alcobendas Parque Bomberos (fire station), less than five minute walk from the hotel which you can see on the right as you approach the bus stop.
The bus runs every 20-30 minutes and the journey takes 10 minutes.
To return to the airport, as I did the following morning, the bus stop is on the opposite side of the main road via a traffic-lights controlled pedestrian crossing.
If you are not in a hurry (and it is not raining) then this is certainly an option.

As an aside, on arrival back at terminal 4, I called the Airport Hilton which sent the minibus to collect me after about 20 minutes for my next night there.