I suppose that more than anecdotal reviews
... you need some real performance data derived from, controlled trials... same boats sailed at the same time/conditions... with different props... This shouldn't be difficult... but the conducting the trials might be a bit spendy. Once the data is collected... the real performance will be revealed and sailors can make an informed decision as to the cost v benefit.
These are spendy upgrades... like going from a standard dacron sails
to a high tech ones. For many the benefits are worth the cost... for others not so.
Knowledge is power. I urge the maker to conduct trials and publish the results.