In case anyone is interested......
I finally got around to changing my TX-100 into an "upside down first stage" configuration last night. IMHO, the hose routing using this config it is certainly an improvement.
For those familiar with the TX-100, the first stage (when "right side up") has 2 LP ports on each side that result in the hoses protruding from the first stage at a slight upward angle (vs. horizontal with the Apeks DS4 or DST).
http://www.divesource.com/apeks/firststages.htm
When mounting the 1st stage upside down, the LP ports are now at a slight downward angle. This is a definite improvement for my primary hose, since I am using a long hose that runs from the first stage down the right side of my body. The hose does not protrude as much as with the "right side up" config.
Another improvement is that I don't have to use the LP 1/2" port for my reg hoses. I am now using it on my left side for my BC inflator hose (using a 1/2" male, 3/8" female port adapter), since the 1/2" port is the one closest to my body.
It was extremely useful to check out the 2 configs with my BC/tank/reg on in front of a mirror...really helps in deciding on gear config decisions. Hope to try things out in the water this weekend down on Cape Cod.
Anyway, thought this might be helpful to someone......although if no one is interested, I guess it's kind of like a tree falling the forest with no one there to hear it.....