Re: Double Bass Pedal issue
Think of it in physics terms. You have one beater connected directly to a pedal. On the other hand, the other beater is connected to a separate pedal located some distance away via a connecting rod (driveshaft).
The pedal with beater only has the weight of the beater to contend with after being depressed. The one using a connecting rod has the weight of the rod affecting the swing as well. Hence, it rocks a little less back and forth.
As far as the beater not moving at all when depressing the slave a bit, I think the problem is that you have too much slack in the chain/belt. That excess slack has to be pulled first before the beater begins to move. So if you remove one of the linkages or shorten the belt to take out the slack, you should get a better response.
I wouldn't invest in a better driveshaft like the Trick for the simple reason that it'll probably cost more than your pedals. Better to conserve your money, practice and when you feel you've maxed out your performance or want a change, upgrade to a pro level bit of kit.
"... As war machine, crushes their balls, God have mercy..."