Cutting it brief, there is nothing extraordinary about the reviewed coolers from Spire from an overclocker’s point of view. Their only good points are universality (except for the DiamondCool) and certain originality of the heatsinks, although the latter thing can hardly appeal much to a potential buyer.
Now, about each cooler, in brief:
The DiamondCool is the least outstanding model among the pretty mediocre coolers from Spire. Its average cooling performance and high level of noise cannot appeal to a potential buyer, let alone an overclocker. The lusterless results of the DiamondCool can only be justified somewhat by its rather low price of $26.
The VertiCool IV model would have done better if it had four heat pipes on both sides of its copper heatsink rather than two as it has now. This cooler doesn’t prove really worthy of its price even with two high-speed fans.
The Fourier III and Fourier IV are the most interesting products of the company. The aluminum Fourier III seems to be preferable in terms of weight and compatibility with mainboards as well as in cooling performance. This cooler is also cheaper than the all-copper Fourier IV. But don’t forget to turn their fans around right away!