A few different manufacturers make them. I myself have a box of Polycase ARX Inceptor .380 ACP bullets my brother gave me because they wouldn't feed in his pistol.
My personal stance on them is simple, if they're everything they're marketed to be, then why haven't they been adopted by Law Enforcement and especially the Military? I imagine that the Military in particular would be all over them since they supposedly offer all of the benefits of JHPs yet wouldn't violate the Hague Convention's treaty involving the restriction of expanding bullets on the battlefield.
Furthermore, even if they worked as well as they're supposed to, then JHPs could still be better, assuming that it's possible to engineer a bullet that expands in such a way that the petals are aligned the same way as the angled cuts on the non-expanding bullets, thus producing an even larger wound channel.
Overall, they're a cool idea, but I doubt that they actually produce the same dramatic results inside of living tissue as they do inside of Ballistics Gel, otherwise they would have been adopted by the FBI or the Military by now.