So far I've brewed an ESB (in Primary... gotta update my sig) and a British-style Brown (Kent, Fuggles, Laaglander Darke DME, Gold LME, and second runnings from my ESB with Scottish Ale yeast pitched after the Burton Ale Yeast declined to ferment).
The slits go face down, I just put them face up for the pic to show off the stripes. I used pliers to slightly pinch all of the connections. They fit together firmly enough that I can stir the MLT without much worry, but they can be disassembled for cleaning.
I'm thinking that the diagonal cuts give each slit a larger area to draw hot liquor and thereby make it less susceptible to stuck mashes. Ironically, my very first mash got stuck! But I'm batch sparging so I just stirred it around and re-verlaufed. Oddly, after that one stuck one, the next three sparges went off without I hitch. I'm just chalking up that first stuck sparge as "one of those weird random things..."
I have the stuff to run two pipes down the center for fly sparging. I'm not there yet, but I have an eye towards that in the future and I am ready for when that day arrives.
For what it's worth, although it took a bit longer, I found the All Grain process to be much more satisfying. I kind of felt like Extract brewing is somewhat of a pain in the ass, with more sterilization than brewing. Not so with All Grain! I really felt like a brewer! In fact, I'm half tempted to go off and read a bit about the malting process!
