Quoted from bobukcat:
Shaker maybe, knocker not really unless they use it in ways we've never seen before. I wouldn't expect it to be firing when I'm in a multiball except maybe one time if I hit a replay. I haven't played a Houdini with the shaker in it so I don't know what triggers it. Since the offer is so good (it's like getting the power supply free if you buy the shaker and knocker kit) I'm going to order all three and see if it makes a difference for me. I don't have the fluctuating line voltage like some others do and my lower catapult accuracy is 98%. The upper one shows it's only at like 75% but I have NEVER seen it miss so I don't know what's causing that number to be so low.
The shaker uses a lot of power so if it is firing at the same time as the magnets and coils and flippers (likely during multiball) it will also have an impact. Consider if in the mode with the elephant you start a multiball and then nail the inner loop. The catapult will likely miss, and/or you will feel the flippers drop.
I dont Really care about the catapult -that- much, mine makes it probably 95% of the time, but the flippers bother me. For $150, that’s a steal at twice the price.