You misunderstood. As if i dont change my bulbs.
Reflectors are a huge factor with HID. Bigger the reflector, smaller the space. Smaller reflectors are for large grows, with lots of lights. So you can concentrate the light in an area. You get better PAR, and more even spread. Just takes a bit of math, to work it out to your room.
In a tent, bigger the reflector, the better. Where's the light gonna go? Its the spread you want.
In a big room, spread is a waste. For the reasons you stated.
Used to be that a tool's quality, was judged, on its longevity, versatility, how easy it is to use, and effectiveness at the task at hand.
A grow light is a tool just like any other. Where does the average LED stand?
Average LED's are shithouse. To say they're not is a flat out lie.
I still suggest groing some big pumpkins too, or any fruit or vegetable for that matter.
You MIGHT get away with tomatoes and cucumbers. Any fruits bigger than that, its all down hill.
You'd be able to grow great salad greens though