the problem isn't the brake's strength... it the retention and elasticity on the heel peace. every time you land switch the heel picks up slightly without kicking your boot out, and on more price point bindings this causes the brake to deploy sooner than we would like. The STH and FFG (same thing) were notorious for this and is the reason for the redesigned heal on the STH2. Your safe bets from Marker are the griffon and up, the Attack from Tyrolia is solid, and the new STH2 is better as well.
For me i use the jester, jester pro, and the Tyrolia Adrenaline. for safe measure i turn my dins up on the heel by 1 or 2 notches depending on the ski and it's purpose.