They are not as good as stamping in steel but superior to paper and simple to use. The small parts will be locked in place under normal operation:

https://blog.lopp.net/metal-bitcoin-seed-storage-stress-test-part-ii/

I’ve tried them. Prefer stamping. Using a punch is not difficult.

I use one and I’m very happy with it. Simple to use and sturdy.

Read Jameson Lopp’s review and comparison of seed protection devices as he puts them to tests of pressure, fire and acid.