I typically know right away now but a few had to click in context for me, particularly el84 vox types. Alone felt brash, in the mix it all made sense
This is my experience as well. I need to hear a new amp with different cabs and guitars and at different volumes. My ears fatigue more rapidly than they used to, so I need some time to decide if it truly is a keeper.I know pretty quick if I like an amp, but it can be a long process to learn if it whether it ultimately stays. I own multiple guitars. Some don’t match well with certain amps. Also, my ears hear things differently at different times.
No, but I know immediately when it's NOT for me.