the good news is that the better made, higher priced gan or otherwise class d amps are sounding quite good these days, much much better than older stuff, even under big uber high end brand names who have gone there in the past
the bad news is that reviews, esp. by the commercial audio press, online, or in print, will only get you so far, as they have mixed incentives to report the whole truth, nothing but the truth, and legit and useful comparisons that buyers likely care about
auditions (ideally in home, in your own system) are key, but they cost time energy and money... that being said, the good news above is indeed good news, and the differences in sq between different units may be relatively modest on all but very good very resolving systems... on many systems most modern options will be very good in producing glorious music, especially when direct comparisons are not at one’s disposal
i have gone back to the budget gan mini 5 - listening to this very modestly priced amp with various dacs i have laying around, soekris, pontus, audio mirror doge... in all cases there beautiful reproduction of music without typical distracting hifi nasties