ARC LS7 vs LS16/I

Agree with hifigeek regarding the need to have quiet gain for phono stage.
Disagree when it comes to a 15 to 20 dB gain line stage.
But it's just me.

Die hard audio research fans here will tell you whichever newer model, in stock form, will sound better than the old one. You should even "use the stock Sovtek or EH tubes that Audio Research handpicks for you when you send it in."

LS16 has "JFET input stage followed by a cathode-follower/output driver stage utilizing two 6H30 twin-triodes" In English: NOT PURE TUBE.

I have not heard a line stage with JFET input that sounds natural at all. 6H30 unless used with mega current sounds thin. Not sure how Audio Research biases them.

Look at LS7, all tube, only a constant current source for 1st gain stage. All 6922 and no 6H30.

I have not owned either models. Only LS1, LS2B, Reference 1, SP10ii. Current I don't own audio research preamps anymore.

I was referring to hifigeek's comment about the advantages if jfet input/ first gain stage. It's quieter than tube implementations.
But if its line stage and not phono I never ran into a case where I think a jfet line stage sounds better than all tube.