Ha ha, I believe RN by stating the S5 will achieve all said goals.  I think some people just love the weight and style the SAR4 brings.  I believe I will love both of these knives. 
I'm just messin' with RN.  You're right that lots of quality knives will do similar work at a cheaper price.  One of my favorites in this length is the Ratmandu.  Not as hefty a blade, but a workhorse nonetheless.
That said, the SAR4 does have a unique feel all its own.
And just in case you missed the news...
THEEY'RREE BAAAAYAAAACK!!!  <img src="/ubbthreads/images/graemlins/laugh.gif" alt="" />
http://bussecompanystore.com/mm5/merchant.mvc?Screen=PLST&Store_Code=BCS