I use OFX between USD and EUR. All is good.
It certainly is uncomfortable sending your money into the ether the first time. Start with a small amount to prove the pathing, and it's no different to me than a domestic money transfer, now.
The last hiccup I had was around Brexit, because they were UK-based. But it was sorted quickly, and their customer support was quite helpful.
I did use another transfer platform before, but they ended their US support.