Okay so I guess I have permission to proceed. Lets start with Element Holders.
Element Holders have been around for a long time. They are extruded refractory components that fit into channels cut in the brick and are designed to protect the brick from damage and make element replacement easier.They are not patented and may be used by any kiln company that chooses to use them. So, why doesn't everyone use them?
One of the biggest arguments for not using them is the restrictions they impose on the design of your elements. Most kilns have two element grooves per brick. Kilns with element holders typically only allow 1 wrap per brick. There are "quad" systems available that allow for two wraps per brick but they add significant cost to the price and also add a significant amount of mass to the firing since they are much denser than the brick. When you have the element holders that only allow one wrap it forces you to make some compromises on your design. The first is the gauge of the wire you can use. For example, on a typical 10 sided top loader you may use 14AWG and 15AWG wire whereas in kilns with half the slot length you may need to use 17 AWG. Smaller numbers are thicker and if you know anything about element life, thicker is better.
When you have more wire to work with you also have the freedom to balance the elements. The top and bottom of your kilns naturally firer cooler than the center. With more design options you can balance the heat better in the kiln by designing the top and bottom elements to run a little hotter. This allows you to have an even firing kiln without the use of Zone Control which I will talk about latter.
Another benefit to having more wraps in the kiln is you have more loading options. It is always recommended that you have at least one element radiating between kiln layers to avoid cold zones and allow your ware to be exposed to the radiation emitted from the elements. In a kiln with 2 wraps per brick those elements are every 2" to 2.5". In a kiln with 1 wrap per brick they are spaced every 4.5 inches which gives you fewer loading options, especially if you are firing shallow items like tile and plates.
While we all hope nothing goes wrong in a kiln the fact is occasionally it does. We all know some one who for whatever reason has over fired their kiln or got a bit of glaze in the element grooves. If a bit of clay or glaze gets in the groove on a kiln element holders it will fuse the element to the holder which can be very difficult to get out and often involves having to cut it out of the groove before you can remove the contaminated holder out to replace it. If the kiln over fires enough, the holder can warp in the groove and the only way to get it out is to chip out the brick holding it in place and then replace the brick and the element holder and the element.
Yes, element holders can protect the brick from careless impact by shelves when loading and yes it most likely is faster to change elements but most manufacturers agree that the benefits of element holders weighed against the liabilities is not in the best interest of the customer.
I am going to stop now primarily because it is 5:30 and I want to go home but also to see what the response is. The last thing I want to do is screw up a forum. If the overwhelming response is for me to stay out I will.