RE: Sling Stix or Regular Sling...???
Well, IMHO the best sling out there is the TIS(Tactical Intervention Specialties) Quick Cuff Sling. It is a nice wide nylon sling with a cuff worn on your arm. It makes you amazingly steady in all positions.
As for steady stix, I don't use them, but my dad swears my them. I use the monopod and really like it's steadiness when used with the sling in higher positions.
The tall bipods and tripods are great, but really take an extra person to deploythem.