Hi Raul,
Thank you for your an inquiry regarding Samsung QMR and QBR series professional displays.
In summary, the main difference between Samsung QMR and QBR professional displays series are brightness and environmental usage.
The QMR series is designed for environments where 24/7 digital signage is sought  ( i.e. shopping malls, shops, airports) with the 500 nit brightness.
The QBR-series with 350 nit brightness is ideal for 16h/day usage in settings such as meeting rooms and for corporate signage. Both series have built-in Magic Info player and consist of five screen sizes from 43 to 75 inches each, HDR+ support and intelligent upscaling. In addition, the displays are dustproof with IP5X certification.
When you get a moment, please give me a call so we can discuss specific model and usage in details. I would like to give you a quote for select model and size. Both models are available in 43″ /49″ /55″ /65 /75″.