I know this may get me some flack here, but we all hear things differently, so take this as you may.
The Fortes soundstage was not as wide and imaging not as pinpoint precise and fast as the u18t was. From all my time with dynamic drivers, my ears find their BA equivalents wider. The Vega vs Andromeda came to mind for me immediately with regard to the Forte vs u18t. The Forte is wide no doubt, but I would say it’s less wide than my a12 ADEL was, and I would say the u18t was about 10-15% wider then my a12 was.
Clarity was similar between the two, the mids of the Forte sounding more natural and realistic, with the highs sounding better and more natural on the u18t.
Without question I preferred the Fortes bass impact, it was extremely impressive and fast, with a natural decay. The u18ts bass is faster, and to my ears has more detail, but feels much less in terms of impact and emotion.
Vocals of males I vastly prefer the Forte. Female vocals sounded sweeter on the u18t. With some men vocalists, the u18t lacked the same body and impact in vocals.
The Forte has more bite. More dynamic. U18t is more precise, fast, articulate. It’s not as in your face - more subdued.
Again, I really think the best comparisons for general purchase recommendations would be this: Andromeda vs. Vega? Elear (if it wasn’t weird with its midrange) vs Utopia?
Your mileage may vary. I am not a reviewer, have received nothing for free from 64 Audio, and don’t plan on being in the industry in any way. Just a regular dude with mild OCD who had to spend $2500+ very wisely.