Glass lids will retain and moisture better, lengthening the time between top-offs. But, they can also grow more opaque over time with mineral buildup, cutting down the light to plants.
Screen is almost a mirror image: more evaporation and heat loss, but much more light gets through for plants. I use a homemade screen lid and am quite happy with it.
2x20-longs, one heavily planted. Platy rancher. They. Won't. Stop. Breeding.