There are tons of swatch tables you can load up in Flexi. The default is just your basic few colors but you can load all of the different Pantone tables including the newer plus ones, metallic, pastels, plus you can load a huge amount of vinyl and ink specific pallets.
For design, I reckon it depends on what you want. Most will be using Pantone Solid Coated for specifying spot colors or just picking RBG colors that you want to design with otherwise.