Thank you so much for sharing your extensive thoughts and experiences with both of these Kuzma arms! It truly is great to hear from someone who has experienced both of these on the same table with the same cartridge, no lessThe 4pt was the original one 11 inch I think so slightly shorter than ref313. From memory I feel the 313 was a bit more relaxed. It tracked very well and produced a more engaging sound than the SME 20/20, I had previosly , when I first explored purchasing the XL. This was in a side by side comparison, same cart, SME V arm. I think the 313 is defintely preferable to the SME V.
I got the 4pt a few yrs later. It is not a night and day difference the 313 is indeed excellent the 4pt slightly more detailed and slightly more powerful.
The 4pt worked very well with the Atlas and Airtight PC-3. I did compare the two arms with a Benz LP cartridge in each arm and to be honest the diffence was miniimal, the 313 being a bit softer.
Both arms have had upgrades from the ones I had. As with any arm there will be a synergy with the particular cartridge used. The 4pt did not like a Koetsu Coral stone when I tried it. I didn't like VDH Colibri in either one, very detailed but over bright.
btw I had the non VTA ref 313 as I had it mounted on the adjustable tower.
Hope that helps.
I appreciate you taking the time to help me as well as others that may be interested in these arms
Thanks again and best wishes,
Don