Can't see spending $150 on a utility product that doesn't show significant advantages over its competition. If the only advantage is durability, I have used a pair of HKS speedloaders that have probably seen thousand + reloads and have seen safari land loaders from others that have more than that with no issues.
However, they do look damn cool, I am just too cheap to justify them. More power to you if you want them.
EDIT. Wow, after reading, the whole set of eight plus the tray for $165 is a good price. I originally thought the 150 was for two loaders....