I may be a low time private pilot with limited ability to contribute to braoder aviation discussions, but I would call myself somewhat of a super user when it comes to hearing aids. I am 49 and have been using various hearing aids for the last 12 years.
In actual fact, my loss of hearing and use of hearing aids is something that held me back from going for my private pilots certificate - I was under the impression that I would not be allowed to fly given that I am esentially deaf without my hearing aids.
A couple of things I have learnt over this time:
1) Number 1 by a long way: "Hearing aids are not a 'fire and forget' solution. It takes a long time and a strong relationship with a trusted audiologist to get them to work right for you. It is so difficult to explain what you are experiencing and it takes time to get it right. Something that is well fitted in an office, can be unbearbale when the dog barks at home or when you are walking down a street. Keep going back - you pay a lot for these things, expect the service and don't be satisifed until you are happy that they are working as you expect them to.
- take notes as you go through your day and explain this to your audiologist at you next appointment. Do your homework and you will see better results.
- mess around with the app and tell your audiologist what works and what does not
2) Yes, the better technology levels are worth it. Especially when you have more severe hearing loss. Get the best you can afford.
3) Read up about "real ear" measurements - In my experience it makes a signficant impact on how well your hearing aids are fitted and perform for you. Ask your audiologist if they do this - not all do. This was probably the single biggest improvement made for me.
4) Watch this guys videos - excellent info on different hearing aids available.
https://www.youtube.com/c/doctorcliffaud?sub_confirmation=1
5)
Carry a backup pair when you fly.
6) Personally I would not get non-bluetooth hearing aids - phone call clarity alone is worth it.
7) I have used, Oticon, Phonak and Signia. Your mileage may differ, but my Oticon More 1 have been phenominal for me. I absolutly abuse them and they have been going for about 5 years now.
8) Clean them regularly - they are sensitive devices - ear wax gets in there and they need to be properly cleanded at least once a week.
9) Get rechargeable ones.
10) Don't fall for the "You need to get used to them" or "they will not be as good as your hearing before you lost it" - that is BS that frustrates you and will make you not wear them or be satisifed with sub standard service - this is your hearing, your life and your money. Go back again and again and again.
Your quality of life should not be degarded by hearing loss. Mine was for many years and it took a lot of frustration the get it back to where it is today. My hearing loss without hearing aids is severe and with them I lead a perfectly normal life - other than swimming

- but I am sure that will be resolved in the next few years ....
Hope that helps - I am passionate about this!