Hay nets will regulate their eating speed, but hay bags will make it easier for them to eat. So it really depends on your horse.
It depends what you want to do with it. If you are taking it with you to a show then I suggest a hay bagas its less messy but if it's just at the barn then a hay net (or even a hay feeder) are great :) just don't hang them too low
I prefer just putting the hay on the ground but if I had to choose I'd prob go with a net, just make sure you hang it high enough, 3 weeks ago at my barn another owners mate got her foot caught in her net when she kicked the stall cause it was hanging too low, she flipped out and fell and cut her self all up and got many bruises and when people tried to help she ended up giving a girl a concussion and another a bloody nose🙄🙄
So if you go with the net just please don't hang it low
I think the net hay is much better for horses. The big difference for me is the visibility of the food, in a hay net, the hay is self-service without constraint, I find it better on a trip (seen how stressed horses). I agree that hay can fall off the net and go on the ground, but if the net hay is full, there will not be much loss. In a hay bags, the horse can catch him only from the bottom, which he does not do often because it's open up and he does not bother to get the hay down. With the bag, the horse may be eaten less quickly but it will put the nose (the head) in the bag to fetch the remaining straw strands, I think that is not ideal ...
Here my Opinion, I hope this helps :)