I used to own a Mind Gear PR-2X which is like the Nova Pro and have done some research on mind machines since then as well as tried a couple of other machines. First, I found out is that virtually none of the manufacturers are (or were at any time) invloved in any research with their local university or hospital. Second, almost all are basing their products on manuals and studies done by one or two serious makers of mind machines. And third, the Neuro-Science community regards most mind machines as entertainment toys.
Forgive me for being so blunt, but I've been using mind machines for a while and I follow the current news on this stuff. I did end up with one machine and m pleased with it. I also use it with paraliminals and hypnosis tapes and I'm painstakingly putting my own tapes together to work in sync with my machine.
My advice to you? If you're serious about this, then get a serious machine.
Sorry for being so forthright, but I've concluded that most of what's out there just isn't worth it. I haven't mentioned the brand I use because I have a strong bias for it and I'm convinced most makers just haven't done their homework.
Good hunting!