There's a considerable difference in the density of the nugs. I've yielded 1-2oz per plant with the LEDs, where I'm able to get at least double that per plant with the HPS. Just seems like you get another 2-3 weeks of the buds swelling.
You said "yielded", past tense, are you growing exclusively with HPS now?
Back around 2016 when I was building my first COB light, there were lots of comparison grows going on between LED and HPS, but I was reading them in the LED section, so there may have been some confirmation bias. Or maybe photos react differently than autos, but at the time people were claiming that COB LEDs produced as well and often denser buds, even though they did acknowledge they finished faster. For me on a practical level it's moot, HPS runs too hot for my space.
So far the only thing that I've witnessed that has caused them to take longer to finish is cooler temps, but that slows their metabolism and the extra time does not gain them any weight. It's interesting how their "inner clock" works. Some people say transplanting, topping, anything that shocks them will cause them to temporarily stop growing but won't lengthen their finish time, resulting in smaller stunted plants. So far HPS lights is the only thing I've heard that can defy their inner clock and cause them to keep growing and putting on weight.
Unless... HPS is growing them to their natural duration, and LEDs are somehow speeding up their clock? In that scenario LEDs would be another factor that stunts them? Crazy. So many variables, so much to learn. Currently I'm LST'ing, topping, and growing under COBs in soil... I seem to be destined to have very small plants... LOL, which is fine, since I have a small grow space and get the bulk of our meds from my outdoor grow.