So as not to derail the thread on the best/coolest ball locks, here's a related question: What do you think of virtual ball locks?
I don't mind the concept at all - I just think they shouldn't be called "locks." To me, locking a ball means I get a new ball served to the plunger and the locked ball is physically held somewhere out on the playfield until something triggers the release of all the locked balls, typically a 3rd physical lock. But when I only "score" a lock and the very same ball is just handed right back to me, I haven't really "locked" a ball.
I love my BKSOR Premium, in part because of the catapult ball locking mechanism. TKC, however, makes me wince a tiny bit when I score a "lock" and get that same ball right back. Again: I totally love the concept, I just wish it wasn't called a "lock." It's purely a terminology thing for me.
If the screen said things like "First knight challenged" or "First knight ready" when the the first knight marches in and defiantly sticks his sword (then the the same thing happens when second knight and third knight enter), I don't mind the balls being served from the ball trough. Yeah, ultimately no big deal but it bothers me in the same way that folks confusing "lose" and "loose" do (or any of a myriad of others ... like "I'd of" instead of "I'd have" etc.)
[And while I'm on this short little soapbox, I've always considered the gumball machine on TZ to NOT be a ball lock per se, but rather more of an on-playfield ball trough/ball queue since anytime a ball enters at the back of the line, it is immediately replaced with the ball that's first in line. The number of balls in it remains the same with the only exception being when it is completely emptied for 60 seconds during LITZ.]