Kirigirl, Every brand has people who say they have never heard clearer. Every brand has people who say its a piece of junk. Quality is very subjective here. You are the only determinant. Much about the specifications is marketing hype.
Someone keeps mentioning more channels. Bernafon brags it is channelless. Everyone of them says they have the best this or that. Some believe the hype while others grimace.
The biggest variable can really be the fitter.
All the hearing aid companies do results testing. And they keep doing so until they get the results they want. Digital hearing aids are the hardware developed for lower power in cellphones coupled to formulas the audio engineers have known for many decades. As the processors available become more powerful, the algorithms get enhanced. Yet you will see remarks here from users that say they like their 7 year old aids better.
So, find what YOU think is best and you’re the new expert.