Has anyone here on this site had any experience with a Rusko Mfg release trigger for a Remington 1100?

Never heard of a Rusko release trigger until now. But if it works, it works. It could be that someone built it but didn't build enough of them to become well known.

It's not too difficult for a gunsmith or handyman to modify the 1100 trigger to a release trigger so there may be many 1100 release triggers in existence that were built/modified by people we haven't heard of.

If you buy one and the release function doesn't work well, you've still got the trigger assembly that will, or should, function as a pull trigger by just removing the hook. So it's not likely that you would lose all your money if it didn't work as claimed unless the whole unit is just a piece of junk, but that's not likely, IMO.