The SC you choose depends on what you want. The Vortech has all of its power in the top end. Otherwise the JR puts out more power in the middle of the power band...where you would use it most during DD. A friend of mine has a vortech SC for his maxima...you only feel it kick in for the last 1000 grands worth of RPM...he already says it was not worth it and wants to sell it.
I would get the JR...but that, of course, is only my opinion.