What are the differences ?

Possibly - but you will have to do some listening to your favorite LPs! Sapphire is certainly stiffer than aluminum! Maybe more low-level detail?

The problem in answering this question is that the cartridge probably sounded ratty when you last listened to it, which is why you sent it in for a rebuild, so it may be hard to remember exactly how it sounded compared to the new one.  That said, I had SS work on 2 cartridges for me and I was very pleased with the sound when I got them back.  I had a different situation in that Peter only replaced the stylus and not the cantilever on mine.  I didn't ask him to do this, I just asked him to do what you think best.  I don't think Peter would have replaced the cantilever on yours if he didn't feel it was the best choice.  My guess is you will install it and be very pleasantly surprised.  

I didn't send the cartridge to soundsmith because of wear but because while mounting it onto my turntable I destroyed the cantilever . Having said that it was probably time for a retip anyhow as I've been using the cartridge for 12 years . 
I asked soundsmith if changing the material of the cantilever from aluminum to shappire would give me better sound he said no , that it would probably track better but that the cartridge would sound as it used to . 

This is Ortofon Salsa 
Why don't you just buy a better cartridge instead of fixing an old one ? 

First of all I don't have to much money and cartridges nowadays are very expensive . If the Salsa were to be marketed today with inflation it would be over 500 dollars .

 Second the fact that its old doesn't mean it can't raise up to meet expectations in camparison to other cartridges on the market . It really is very good .

I would have to spend a lot more money in order to get a.little better performance . Maybe 800 or more . I hope this explains why I didn't go with another newer cartridge .

You know, I have nothing against OLD cartridges, most of my favorite cartridges are old, but they are not refurbished. 

You can buy perfectly working cartridges for the price you will pay just for the new cantilever/tip to retipper. 

If you can accept only MC cartridges then HANA is the one post people are raving about and some of them are under $500. 

I would buy an MI or MM cartridge instead of spending money on refurbishing Ortofon Salsa. 

Talking about equal expenses, or very close. 

I think that refurbishing is not the only option you can get. 

But a cantilever will make a difference, in your situation you can get a better cantilever for your Salsa. But if you like SoundSmith buy his own MI cartridge or something else.  

First of all having only 300 dollars doesn't give me much options . Even the Hana cost 500 dollars . But 300 to retipped a cartridge that I know sounds great in my system with my turntable is not bad , especially considering I'm getting a line contact stylus with a shappire cantilever with 1 year warranty is I consider a great deal . On MM I have a Nagaoka MP110 which for the price sounds great and a very good Grado MI . The Salsa sounds substantially better then both.

I just received my repaired and retipped Ortofon cartridge from soundsmith and I must say it looks beautiful . The shappire cantilever is smooth as a babys butt and the line contact stylus looks really nice . I'll keep you guys updated on the sound as soon as I install it . SoundSmith seems to do really nice work . 

Just mounted and heard my Ortofon Salsa MC cartridge with new shappire cantilever and line contact stylus by soundsmith and it sounds excellent . These guys do great work and I can whole heartly recommend them . By the way the cartridge sounds better then what it used to . I don't know if this is because of the usage and age of the cartridge or a funtion of the new shappire cantilever ( having been of aluminum ) all I can say is that it sounds better by a margin .