@roger,
If yours lasted 7 years, you definitely got your money's worth. I've been told most only last about 5 years with constant use.
Fortunately, my dead hearing aid was only 1 year old, so it was still covered by the warranty. They sent it in, and the manufacturer replaced the inner workings at no charge. I found another audiologist that is covered by my insurance, but it turns out that follow-up visits for fine tuning are not covered now. Normally that is considered part of the purchase price, but if you switch audiologists...
So now I have to pay $100 out of pocket every time I go in. Or else suck it up and go back to the original audiologist, which I am not gonna do. I left because they weren't straight with me on costs. So it looks like I'm screwed either way.
About your question, roger....as far as I can tell, there are several good companies that make hearing aids, so it shouldn't matter what brand your audiologist prefers as long as he/she chooses a model that is right for your exact type of hearing loss. The newest ones are RIC (receiver in canal), which still have the "open fit," but have a tiny receiver (where the sound comes out) under the silicone dome that fits in your ear. This means less distortion because the sound doesn't have to travel down the tube before it gets to the ear. Also, many aids now have two microphones in them instead of just one, which makes them able to pick up sound from more directions...in other words, no "dead spots" behind you.
Hope this helps!