I had a perfect evening last night with blue skies and abolutely no winds.. Ideal for trimming my models!

I found one rather irritating feature when pulling my Suxess through positive and negative snaps, and hope to get some enlightening answers here.

Basically, it snaps WAY faster negative (45deg downline inverted) than positive (from stall turn). Any ideas on why..? Is it simply "just the way it is" with biplanes??
My Oxalys has basically the same snap-speed either way, so I find this a bit puzzeling....