This “difference between models” question was asked and answered on Amazon a few years back. Hayward posted the following vague answer: “Other than the difference in colors there are some minor component differences between the original Poolvergnuegen and the Limited Edition.” (The dark grey use to be advertised as a “limited edition”, but Hayward dropped that and now both the dark grey and regular white/blue can both be found priced at $399).
Hayward is simply engaged in a marketing scheme. To claim the price differential to be due to “minor component differences” without specifying what the significance of the so called “minor component differences” is on performance tells you all you need to know: There is no difference. It’s a common marketing dynamic that ppl will pay more for an identical product believing the pricier one is of superior quality.
More deceitfully, the $399 model doesn’t disclose any warranty information. Instead, it underhandedly directs you to contact the seller for this inform information (whereas the more expensive model links you to a warranty pdf). Consequently, there’s ether no warranty or a very short one on the $399 model.
These questionable business practices don’t end there. In violation of many states consumer laws, it’s one year warranty on the more expensive ..but identical..model is made ineffective if the buyer fails to send in a completed registration form “within the allotted time frame.” California, among other states, prohibits any such condition to product warranties.
Arguably, Hayward is allowing its resellers to promote its products using such tactics. Consequently, it bears responsibility for not exercising the control it could apply to its resellers. As to the unlawful warranty practice, that falls directly at Haywards feet.
In sum, “Buyer beware” is an understatement in the context of the foregoing.