I would suggest that these are not for use at highway speeds.
Cheap, hi vis, waterproof. Couple this with windbreaker pants and you're good.
What more do you need for those odd days when it rains really hard.
Most of the rain we get in the summer is a light drizzle, or it rains hard for 10 minutes. My Joe rocket textile jacket is waterproof enough for those scenarios (without the waterproof lining).
Rode to Americade one year with a couple of guys who bought cheapie yellow rain suits from Mark's/Cdn Tire.
They lasted a couple of hours before the legs literally shredded due to flapping in the wind. At every stop they were using black electrical tape to keep what was left on them. And yes, they looked like a couple of bumble bees by the time we arrived.
Those folks riding behind them had to dodge bits of yellow plastic flying at them.