Ortho Flex models?

[RhndLev@cs.com]

I looked at a used Ortho Flex yesterday.  It was a "Challenger" and was VERY 
heavy and I found it almost impossible to post in it.  Also, the padding 
around the wither area of the saddle was quite smashed in appearance as 
opposed to the padding on the rest of the saddle.  This lead me to believe 
that the saddle put more pressure on the horse in that area than in any 
other.  Is that an accurate belief?  I assume different models are set up 
differently -- ie more of a centered seat for better balance during two point 
and posting -- but the smashed padding in the withers area really concerned 
me.  My reason for looking at different saddles is because of excessive 
pressure on my horse's withers and the area behind her withers.  Are other 
models better/different?  Anyone have any experience with the "Challenger" as 
opposed to the others?

Rhonda