I rode an '11 Ibex 139 for 2 years and loved it to death. And I mean that literally...loved it until I snapped it in half on a bad landing 2 months ago. I've since replaced it with the '13 Parks (Ronix's replacement for the Ibex, with a few shape changes) and actually like it a little bet more than the Ibex.
Like others have mentioned, both the Ibex and the Parks boards have a bit of a "learning curve" associated with them. Neither of these boards are particularly fast, and should be ridden as such. When I started riding the Ibex, I rarely got good pop because I was trying to fly into the wake with way too much speed. You've really gotta emphasize a progressive edge with the these boards - great line tension and standing tall through the top of the wake will give you the big vertical that these boards are known for.
The biggest difference between the two, IMO, is that Ronix mellowed the rocker out a bit when reshaping the Ibex into the Parks. The Parks rides faster than the Ibex, but I haven't found that it pops any less. When it comes down to it, either board is a good choice. Personally I'd go with the Parks if you can find the right price. I found mine through a store on Amazon for ~$280.