I can tell you that the charcoal basket is one of the best mods you can make, especially if you are using the SMJ silver. I smoked with just an ash deflector for about 4 months prior to building my first charcoal basket. The difference in temp control and fuel efficiency was night and day. The charcoal when basketed burns cleaner and leaves less ash.
Welshrarebit,
You will likely find the "basketless" mod (if it works), a interesting and inexpensive mod. The materials will be a recycled tin can, which is cheaper than building a basket. It will also allow you to have more charcoal in your mini-WSM. The blanket mod will cost some money up front, but will save on charcoal in the long run. However, with the 40 pounds of charcoal for $9.98 special at Lowes right now, it may take a while to recover the cost of that mod.
Basketless