No disrespect to Naim owners. I once considered the Naim Supernait at one point and contacted a guy who is selling a used unit who coincidentally also has the LFD LE III for sale. He mentioned the LFD is overall more musical with better vocals that have more presence compared to the Supernait. The advantage of the Naim Supernait lies in the added features of built-in DAC among other things. The XS is close to Supernait's sonics whereas 5i slightly lower in performance so you can expect how they would fare with the LFD. Another dealer also informed on the same findings. I have listened to the LFD and can verify on its musicality but have no chance to compare it with a Naim side by side.
Of course, everybody has their own taste and listening preference so YMMV.
Of course, everybody has their own taste and listening preference so YMMV.