Converting your fluorescent lighting to LED lighting is a great move; you save money on electricity and don't have to deal with the mercury disposal issues that fluorescents can present. You also get a chance to change the lighting fixture so that the light you get is also better for the area it is illuminating. For high bay lighting, two common styles are linear, which is rectangular, and "UFO," which is a round fixture that resembles one of those disc-like crafts in science fiction movies from the 1950s. The different fixture types work better in different situations.
The Height of the Ceiling and the Light
The two types of fixtures work better at different heights. This has to do with the amount of light they appear to give off (or the lumens and brightness) and the power (or wattage) of the bulbs. UFO lights tend to do better on lower ceilings, while linear lighting does better on higher ceilings. If you have a very high ceiling in your facility, then a linear light may be better.
The Shape of the Room
While you could use either fixture in most spaces, linear lights tend to be easier to fit in narrow rooms. The rectangular shape of the fixtures is easier to fit into narrow hallways and similar spaces. The shape of these lights also helps avoid uneven lighting; the UFO lights can create a spotlight effect if they aren't spaced well, and that spotlight effect can make the hallway or other narrow space seem even more cramped. Linear lights give you a more even light.
Need for Focused/Directed Light
However, sometimes you want a spotlight effect, and that's when UFO fixtures would be perfect. If you space the lights closer together, you lose the spotlight effect and have a more consistent light level around the room. But if you want areas to have more light than others, a UFO light aimed at that spot is what you need. The UFO fixtures do tend to be easier to direct in a certain way, such as toward a corner or elevated walkway; linear lights focus the light downward only.
These LED fixtures will help you save money and avoid making the facility too hot, as can happen with halogen and incandescent bulbs. The sooner you can convert the lighting to LED, the sooner you'll see the benefits.
To get LED high bay lights, contact a lighting store in your area.