Concur, I have used them in many applications. The one I took off was leaking at the front, and there was RTV there. I researched this a bunch, and Felpro recommends no RTV. I installed a new one with no RTV and it still leaked.
I believe the felpro gasket is silicone, but I can't confirm this. And getting things to stick to silicone can be difficult. It could be the original one that was leaking did not use a silicone based RTV, and that was the issue.
I also saw a lot of recommendations that the OEM one is better in this particular application. And it may be that people have had better luck as it appears to be a nitrile, or non silicone rubber. So I'm hopeful that the third time is the charm, this time using the OEM gasket.