Here is a comparison between 500 VS 1000 lumens flashlights to help you make a better purchase decision.
How Bright Is 500 Lumens
Features Streamlight TLR 7A
500 lumens is bright enough to lit up a room environment even hallways, but has limited beam range in outdoor environment past 50 - 100 yards.
How Bright Is 1000 Lumens
Features Streamlight TLR 1 HL
1000 lumens is brighter than 500 lumens light for sure. The user can definitely see more in the dark using a 1000 lumens light, but the differences for long distance beam reach isn't all about lumen intensity.
It's actually all about candela performance. It's the light beam's ability to reach far to ID subjects. You can learn more about here.
High candela light VS Low candela light - Tighter beam pattern light can throw the beam further to lit up a target even if the lumen intensity is lower.