I own the T+A PA 3100 HV - their integrated amplifier (and their DAC 200). So, I am clearly biased and you should take my comments as such.
There is a reason I own this brand. I upgraded from their R series integrated (very nice sounding itself).
I evaluated many others and sonically preferred the T+A. I found it smoother, ever so slightly warm of neutral, and resolving without being clinical. Build quality is very high, and the company has been successful and growing for decades. I understand they have about 100 engineers (12 with PhDs on their team). This is not a fragile company like so many are.
I can’t speak to Naim as I haven’t experienced that brand at this level.
I have to believe the preamp you’re considering is a step above what is in my unit.
Do be aware the HV units are quite heavy.
Good luck and let us know what you decide.
best,