Only bad thing I've heard about the A150w is they are noisy, but I doubt that's the reason they discontinued them (although my understanding is the A160 is much quieter). It's just part of their business model, it's the same reason they don't still make the original iPhone.
Kessil is an innovative and aggressive company at the forefront of the industry. They can't continue to build and support a previous generation of products and push out new products at the same time. They want to encourage customers to upgrade, purchase and promote their latest technologies, and offering their previous generation of products would be counter productive.