I've just finished reading Stan Telchin's book, Some Messianic Jews Say, “Messianic Judaism Is Not Christianity”: A Loving Call to Unity, where many of the same concerns are raised. One of our large local Messianic congregations seems reflective of the Messianic movement in general in struggling with this issue. I'd say the movement is growing and is here to stay, and I'm actually very encouraged by this, but it has been fascinating to follow the history of the movement and see some of the issues it's had to deal with.
It can be a very delicate subject in terms of cultural identities, Jewish outreach and Jewish and Gentile relations, and legalistic tendencies. Indeed, and perhaps in attracting large numbers of Gentiles to the movement, there has been a tendency for the adoption of some attitudes and practices quite reflective of the first influx of Gentiles into the Christian faith. It is sometimes difficult to sort through errors in attitude (an "holier than thou" factor, if you will), inappropriate legalistic requirements or pressures, and a rather wonderful appreciation of both Biblicalness (reconstruction of Scriptural forms and practices quite in keeping with our Reformed tradition) and Jewish culture (whatever that's determined to be).
I would heartily recommend reaching across the aisle here at CF to the Messianic congregational threads and viewing their great love and respect for G-d, and how some of these issues are approached. It's very true that a tendency to talk from above one another must be guarded against while graceless legalistic requirements are also to be avoided, but I view that Christianity can merit from a reconnection to its Jewish roots in ways that encourage a deepening affection for Biblical forms and just what we Gentiles have been grafted into.
You are quite correct to caution a wowing with rhetoric. I'm rather enamoured of words and even theological jargon. It's a struggle for me not to be overwhelming or overpowering in my eccentricities. Whatever gifts and graces we possess have a right way and a wrong way of both expression and service, and caution must be urged to humble engagement with others. Still, I've heard the clarion call that "Jesus was Jewish!" and find it a helpful aspect of regaining some of our Christian distinctives particularly lost in our American homogenization with worldly culture. For me the key is to make it a reclamation of Biblical norms in unity with our Jewish brethren, and not a crusade to rabbinic traditionalism.
-kib