what makes SME arms so special ??

I would appreciate a short description of what sonically can describe the most recent SME family tonearms.
??? I went with the full blown Origin Live RB250. What an arm for the money.
It is not so much the arm itself, but it is what is inside it that makes it special. If you wonder what i'm talking about, try reading the post titled "Audiophile Oddities" regarding a YBA preamp. If you were to crack open an SME, i think that you would find something very similar. Sean

PS... Sorry, i couldn't resist : )