20% is a fine level of protein. 16% protein which is common in layer feed is the minimum level and in some cases actually end up not being enough if your birds also eat a lot of low-protein treats. Additional protein helps with growth (which is why chick feed is higher protein), feather regrowth (after molting) and general health.
As for the quality of that specific brand of feed, it is hard to say. There are so many brands that are regional or local only. I looked up Horizon Acres online and they didn't show any nutritional data which is very important. If you could get pictures of the nutrition info for the types of feed you are considering, that would help.
FYI- Unmedicated chick feed, grower feed and all-flock are virtually the same. They are all higher protein, low calcium blends. The biggest difference are that the first two are virtually always crumbles to feed smaller birds. The latter is usually pellets for adult birds.
I originally used layer feed, but it became untenable after a while. Switching to "feather fixer" (another high-protein, low calcium blend) for winter molts and back to layer in early spring was a hassle. Then, when I brought in a new generation of chickens and they were at different stages of life and had different laying schedules was confusing. Elderly hens lay less often- do they need the same amount of calcium? Finally, if you have roosters then layer formula is just not the right answer at all.
I ended up switching to all-flock + calcium (oyster shell+egg shells) on the side and once new chickens graduate from chick feed, they stay on this feeding regimen for the rest of their lives. They regulate their own calcium intake naturally. Easy peasy.
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Edit: Found the nutrition info. It was
pretty well hidden. The Horizon Acres all-flock is pretty comparable to the Nutrena Naturewise all-flock that I use. One number did shock me. Usually, you see ~1% calcium for low-calcium blends and ~4% calcium for layer blends to support egg production. HA all-flock has 3% calcium. That is odd.