This container is not completely necessary, you can grind grains in the wet container. However, if you can afford to purchase this container there are a few good reasons to do so (listed below). I've included pictures to show you the size differences between this container and the wet container, and I've also included a picture that shows the scratches that occur from grinding dry ingredients.Here are the reasons you should consider this container (why I like it and purchased it):1) It's designed specifically to mill grains, spices, and other dry stuff. They have engineered the container to move the ingredients from the bottom to the top allowing for a fast, efficient and thorough milling (as opposed to the wet container which is engineered to move the ingredients from the top to the bottom.....this is a simple explanation, but don't take my word, read the Vitamix website). This container produces flour (at least from the hard red wheat berries I've used) that is similar in texture to a stone ground whole wheat variety (that is to say dense and not very fine...see drawbacks for more).2) Because it's specifically designed for efficiency in milling dry goods you are able to accomplish this task at a faster rate than with the wet container (which can result in less wear & tear on the motor and less heating of the ingredients being milled....the heating issue is especially important when you're grinding flour).3) Grinding hard items (like wheat berries, almonds, spices, etc.) can actually cause small scratches to form on the inside of your container (see my pictures of this container). This is mostly cosmetic, but I didn't want to scratch up my wet container since it's sometimes important to be able to clearly see what's happening inside your soups.4) Some users have mentioned that ground spices can be hard (if not impossible) to completely remove from scratched up sides of the container. Meaning if you grind cinnamon or star anise or another aromatic spice you are likely to have small bits of it stuck to the sides of your container for a very long time (note: this happens more as you use the container more). Apparently it's really not a huge issue with flavor because it's only very small bits of the spice (although some users have complained about this being a bigger issue than others) so it shouldn't muck up a flour grind or anything. But, I'd rather have a dedicated dry container to muck up since the grains will already be scratching the sides.Here are a few drawbacks:1) If you're looking to create bread flour or AP-like flour you may need to sieve the final product further. This container produces wheat berries ground into a consistency similar to a local stone-milled whole wheat flour (as opposed to the Gold Medal Whole Wheat which tends to be finer). It does a solid job of grinding almonds and spices as well, but similarly does not produce finely ground powder (you will need to sieve to achieve that in most cases....but not all).2) It's not cheap....I can think of a lot of ways to spend $100+. In fact, if you want an easy work around you could just purchase a cheap coffee grinder to grind up all of your dry ingredients (and your coffee of course!).