SoundSmith cartridges how good?

Craig, I seems that the real improvement in the strain gauge cartridge is it's tracking performance. It more readily follows the groove with according to sources much less record wear. I would assume the term solid state means more accurate in this regard w/o tube or other colorations. As for what sounds better is a matter of taste, accurate is not always better. 
As for stylus replacement it is important to note that unless you order your strain gauge with extra styli you have to send your cartridge back to Soundsmith as each stylus has to be matched to the cartridge. So, it is no different than a moving coil or Iron cartridge in that regard. I would order mine with one extra cartridge.

In the future it would be great if we could keep the negative comments to ourselves until we know for sure it is a pattern.

That's a lovely sentiment, but it makes no sense (if no one posts until there's a "pattern", how could a pattern develop?) and as demonstrated by the numerous posts in this thread, happy customers will come to the defense of a company they've had a good experience(s) with.

I bought my Aida II used and it did not come with a stylus guard. I wrote to ask if I could purchase one and they sent me one for free. 

I had a cartridge retipped by them and it was also a positive experience. 

Greg double blind testing will reveal the unposted pattern..

seriously, Peter is a fellow poet, dog lover and all around good dude. I have had business dealings with him and his team including touchy rebuild of a rare Benz, nothing but happiness.

Some months ago, there was a thread about hard times Soundsmith has been through because of the Coronavirus epidemics (most likely). Mr. Lederman chimed in himself, or maybe he even started a thread but I am not certain now.

Seeing so many positive responses here, it seems that Soundsmith is, in fact, very respected player with enthusiastic and, probably just relatively, large following. Admirable for a small company heavily leaning on one person’s skills, ideas, and personality.

Would one play a moving iron cartridge through the MM or MC setting on a phono preamp? 

A few years ago, VPI was really touting the Soundsmith as a good match for their tables, with I believe, the JMW 10 tonearm.