This type of set up has been used for decades and has many years of proven data showing bigger yields, better growth & quicker ripen times. That’s why the MH/HPS combo is often referred to as the “golden standard” of grow lights.
As a general rule of thumb, HID grow lights like Metal Halide (MH) and High Pressure Sodium (HPS) are most suitable grows where there is at least 5 feet (1.5 meters) of height in the grow space, though it’s recommended to use a taller space for the best results. This is because MH/HPS lights give of a lot of heat and can cause scorching or bleaching if they are too close to the canopy.
HID grow lights can have better penetration into the plant canopy when compared to other grow lights especially the case with 1000w doubled ended fixture. The deep penetration and high spectrums of lamps are what helps to produce heavy yielding crops were used to seeing with HID set ups. The power and colour spectrum of HPS grow lights tend to give better yields than any other type of grow light for the amount of electricity used, with the possible exception of modern LED lights.