No. Life is not simple and neither is buying a bright monitor. Many
factors besides nits can interfere with the visibility of a screen. Computer displays are usually protected by see-through shielding material (glass or plastic) on top of their displays. How this shielding is bonded to the underlying surface can have a huge effect on the amount of glare (reflection) that is created. Anti-reflective coating on the shielding material can also affect the overall illumination. Even the mounting of the internal components of the computer can affect the brightness. So, it is theoretically possible that a display with a high nit rating will be dimmer than one that has a lower rating. To be sure you get what you want, consult your computer professional.
I completely agree. There are numerous variables that make a computer display viewable outdoors. The nature and treatment of the display surface has an impact on reflections and distortions. Optical treatments of the display affect internal reflectivity and effective contrast. Vertical and horizontal viewing angle affects overall usability. Layer bonding and overall LCD design and technology affect clarity and viewing characteristics. And the type of digitizer also has a large impact. Backlight brightness is important, but it is just one part of what must be a well-conceived, well-designed, well-balanced outdoor display system.
I concur, brightness coupled with an efficentlty designed display system is what what seperates a GRADE A hi-bright display system from its competitors.