These are nice lights and might be well worth the money, but D2's if this is the light that you are comparing them to is 2600 Lumens each so a pair would be 5200 lumens. A pair of D2's costs around the same as one Whelen.
You can't compare 1 Whelen against 2 D2s, 2 against 1 right? 2 Whelens are over 7800 lumens, much higher than 5200....Also, I would like to see how much each additional rigid lens is. I think having 4 different lenses is a large bonus, say if you decide to move the lamp or realised you picked the wrong lens for the spot you chose. Or in various off-road enviroments, a different lens may produce better visibility.
Price wise , d2s are cheaper, but you would need almost full extra D2 lamp to equal 2 of the Micro-Pioneers, but they sell them in pairs so now you have 4 ($800), now you need to buy mounting brackets for all of these ($$) ...see where i am going with this?