What are the differences between the Resound Linx2 9 and Costco Cala 8?

I am not familiar with the Cala - or any other Costco-brand hearing aids, but it's my understanding that many of the products being sold through Costco are "made-for-Costco" products, so they are not really the same exact products as those being manufactured and sold under the manufacturer label (in this case, Resound Linx 2 9). Also, the products being sold through Costco are often not the current or most recent platform as products being dispensed by Audiologists obtaining products directly from the manufacturer. They are likely technology that is somewhat dated relative to the most recent products (in this case, the Cala might be more comparable to the Linx products and not the Linx 2). There may also be some programming limitations on some of the Costco products, which might restrict programming access to ONLY Coscto, meaning, you would not be able to go to any other provider for adjustments or programming. 

Costco hearing aids are special, and have several features missing.  They are also older circuits than the ones sold through clinics.  For example, the tinnitus function is missing on all Costco aids, and some of the special noise program features are also missing. 

According to the descriptions of the Linx2 9 and Cala 8 they both appear to be similar. There doesn't seem to be any glaring difference. Our office doesn't recommend buying Costco hearing aids as they are very limiting in many ways. The technology is very outdated, limited programs, and other providers cannot service or adjust Costco's hearing aids.  Although cost may play a factor in the choice of hearing aids, you should consider what is going to work and be best longterm.