You definitely need to test them both before buying! Otherwise find another dispenser.
Do not compromise on that, it’s your money, your time, your hearing.
From what I gathered is that various people mean different things when they say sound quality.
It could be better bass, so loudness. It could be less filtered and processed so more realistic. Or it could be speech clarity.
One thing is most important - they both have to be fit following the best practices in order to give them fair comparison.
And to be really able to say which gives what type of quality. If any. I got same word recognition score in booth from marvel m90 (I have to pay additional 1500 eur and insurance gives 700)nl and lowest unitron which i could get for free (insurance covers completely, cost around 700 eur). But both were fitted using REMs. How they behave in the real world and solve my problems is a different story. That’s the point of trialling.
Because otherwise (not using REMs) you’re at risk of having dispenser give more effort to the one he earns more from and not the one that solves your problems.
Check this site and top link to file with best practices.
If they don’t follow that, run away.
Or file directly
Special emphasis on using REM (real ear measurements) for fitting.
That’s how babys and kids are fitted in order to give them how the sound really sounds like, so they can develop properly.
Why not everyone does it? Because people still pay for subpar service of ‘do you hear me now’ and endless visits and then toss the HA in the drawer if they don’t serve the purpose. Dispenser doesn’t care, he made his profit.