Anyone have experience with Soundsmith’s strain gauge?

I love my blue LED...really. For me, it's just another touch of unorthodox to go w my LT air arm, direct rim drive tt and 93 kg Stacore pneumatic/mass loading support.

So Thermionic, can I answer anymore Qs you might have re SG?

Yes, I was wondering if there’s any sonic differences between the versions of the SG. I see you can pay more for a fancier preamp and you can pay even more and get one from their reference line. The other question I have is how exactly the stylus replacement works? It is like the Ortofon cartridges?

Levels of preamp if you're just using the solitary analog SG-based source.
For those w cdp, streaming, tape, AV...it's not really practical.
Cannot comment on those different units, I have the energiser-only "entry" model.
Stylii slot in and out on a screw-in assembly, c$1k for replacements.

I think @spiritofmusic has covered this well.

I have an SG-210 system and have used various cartridges in the past: Lyras, Clearaudios, Ortofons...but the most recent vintage of those is a Titan 'i', which I used with an Audio Research Ref Phono, with Teflon caps, NOS Mullard, Siemens, Telefunken and other tubes. But I can't compare these carts, it has been too long and much has changed -- I moved, have a different listening space and system.

What I can say is this. The SG is truly exceptional in my experience, but it does require very careful setup to get best results. I know everyone here takes setup seriously, of course. But small adjustments matter. Dialed-in, this cartridge allows the music in the groove to be presented without (to me, anyway) impediments. Small little things in the mix that were previously vague or entirely absent are just there, as natural as anything else in the mix. Timbres and instrumental textures are laid bare. This cartridge just doesn't stop delivering the music, in a holistic and coherent fashion.

I am sure some would prefer a SoundSmith MI cart, or a fine MC from another source. We don't all have the same tastes, in music and sound. And I myself was on the fence for a while before electing to go all in. But the SG is truly special, and LPs a greater source of delight than anytime in perhaps 50 years of spinning vinyl doughnuts. Of course, YMMV.

Jeff B