can it bee that audio research vsi 75 has lack of open highs/mid ?

i auditioned twice one on display which offered me in kind of attractive price..
did it with my vinyl records
280 hours of working with kt150 tubes.
we tried it on several speakers .

some of them the sound was more open, but i still felt that it’s not "open" and natural enough.

i know that arc saying that the amp need around 600 hours for break in, but still i would expect something more after almost 300.
we compared it with kr audio va 900 which i think was a bit more open, but i think also a bit more aggressive.

does someone have another experience with this integrated amp?