I don't have either, but I'll throw in my two cents. Check out part availability on the SunSun. If you can get parts really quickly, it might be a good choice. My LFS
carries Fluval parts, so when it comes time to buy a canister I will go with Fluval.
You'll want to check out videos on how both can be disassembled and cleaned. Which one looks easier to you? It really comes down to what you like and think will be best for your setup.
$100 is a screaming deal for a 406, btw.
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