I had assumed that you were referring to bow riders, where the gaps between brands is more narrow (only so much you can do with a bow rider after all).
I am surprised that you consider the Larson and the Regal to be similar. I don't think they are intended to compete with one another. Larson is a price point brand, where Regal is a higher end brand. I have never owned a Regal cruiser, but from going to boat shows, they are by far my favorite express cruiser (although I am not crazy about their two tier cockpit designs in the sub 30' models). I think if you look closely, you will see that Regal puts a lot more effort into the details than almost any other brand, and the workmanship is top notch. Just poke your head underneath a helm of any Regal boat (runabout or cruiser) - the wiring is a work of art.
Nothing wrong with Larson, and they do have a great hull design (duo-connic), I am just saying that I think the extra cost of a Regal is warranted.