I too had serious bucking problem with my sabre2, a rigger changed the steering lines and made them shorter than they were before. When I lenghtened them back to where they were, the problem was gone.
170 loaded 1.24 at the time.
We'll see if I have to lengthen my new 150's steering lines too when I start using the fronts on it.
to the opening issue, I noticed more off heading openings later on with the canopy, probably something to do with line trim cause the canopy had 500-600 jumps on it without line chance at that time.. But those off headings were mostly like 90 degrees max so isn't a big deal. Not hard(not a single hard opening for 190 jumps) but doesn't take forever either. Closed end cells open nicely with a gentle pull from rears. I like it, but can't really compare it to anything else than pilot as I haven't been able to demo a safire2.