So, you've wandered around the site and just can't decide which set-up matches your cooking style.  Well. here are a couple key differences between the Adjustable Rig and Woo3 that may help you decide.

• The main cooking grid height for the Woo3 is a smidge below the felt line.   For the Adjustable Rig, it’s two inches above the felt line.   For direct grilling purposes, both are an improvement over grilling at the fire ring.   Some prefer the felt line, as it is a break point with the base and dome.  Others prefer the higher dome location as it provides slightly better temperature control.
• The Adjustable Rig offers more set up options for multi-level cooking.   So if you plan to do big cooks, it’s a better choice.
• Add a ceramic stone and either, Rig or Woo3, can be set-up for an indirect cook.
• The Sliding Grid system is an option for the Adjustable Rig only.   With the Woo3, you can get a slide out set-up, but it’s not as clean a set-up.   It’s grid-on-grid.
• Both the Woo3 and Adjustable Rig are not difficult to use.   The learning curve on each is quick. 
• Both offer options to go higher in the dome. 
• The Adjustable Rig has the greatest potential for grid surface, over 1000 square inches.   Not sure what you’d do with all that space, but it’s worth mentioning.
• The Spider works best with the Adjustable Rig, as they were designed together.
• The Woo3 will hold a wok.  
• Since the Adjustable Rig’s main grid is above the felt line, it is easier to add wood chunks and chips to the lump.

1. If you plan on doing traditional grilling and barbequing on a small scale, the Woo3 is all you need.   Maybe add the extender/grid for a little diversity.
2. If you are a grilling and barbequing enthusiast or plan on getting creative with your cooking, the Adjustable Rig and Spider are for you.   The Rig and Spider are more versatile than the Woo3 pieces.