Opinions appreciated: check valve vs anti-siphon holes in overflow returns

[gregzz4]

I am looking for input from seasoned users who have either check valves or drilled return lines.

I have read, and read, and read, for 5 months online. I've seen horror stories about check valves failing. I've also seen the same said about drilled holes due to snails and such.

I have flow-tested my system, and am happy with it so far, but would like the option of placing my 3/4" loc-line nozzles either below the surface or just skimming.