No, I wasn't, but it crossed my and my husband's path on two fronts at the same time, so we stood up and took notice. The story of how I became aware of the HRM can be found here:
How I Became Aware of the Hebrew Roots Movement. There is a series of short articles there that detail the questions that arose as HRM doctrine was presented on an online digest I was a member of several years ago.
When evaluating any belief system, it always comes down to two things: Who do they say Christ Jesus is (Deity or not), and do they try to take away from or add to the Work of the Cross. After figuring out where they stand on those issues, then there was finding out where their beliefs come from, and it turns out that HRM theology draws heavily from SDA and the former Worldwide Church of God (Herbert Armstrongism), along with a picking here and there from Mormonism, JW, and even some doctrines from the old cult, The Way International. Then of course there is Judaism and Talmudic input as well as influence from the Kabbalah. Many in Law-keeping sects will tell us how they 'don't belong to' any labeled belief system, and that they are where they are from studying the Bible alone. That's a load of hooey. At some point, they've hooked up with teachers of the Law and are taught to view everything through the lens of the Law instead of the lens of the Finished Work of Christ. I assert that many adherents don't know where the teachings that they hold to come from, but, ironically will examine closely Christian history (from Law-keeping sources, of course) to find out all they can about its 'corrupt' origins. Yet they won't apply the same level of scrutiny to their own belief system.
I didn't really want to get into the fray about it - but God wouldn't leave me alone until I put JGIG together. And it's been a good thing =o). The site has provided much encouragement to friends and family of those in the HRM, and has been a good resource of grace and hope to those who have come to the end of themselves under a Law-keeping mindset.
The goal has not been so much to 'refute' the HRM as much as evaluate and build believers up in who they are in Christ, giving them the tools with which to discern not only the HRM but any belief system. I'm finding more and more that having a good handle on just what the New Covenant is and understanding the High Priesthood and Work of Christ is key in all of that. The entirety of the Word really is all about Him \o/. The result has been a deeper love for Him and a desire to share the Gospel of Grace - the Good News - more and more.
-JGIG