I have 2 (soon the be 3) GCC Cutters and they have earned their keep.....Great Cut is just cutting software so you will need some graphics software....If you do not want to buy software, you can use Inkscape and import your files into GreatCut as a pdf...
As far as a 12" or 15" cutter, it will suffice but you will waste material with some designs.....Having the option to use 20" material often saves you money.....If you cut a lot, the money you save on material will pay for the upgraded cutter.....
Plus even if you do not plan on doing signs or wall vinyl, you will from time to time...Our family and friends often get cut vinyl items as gifts....The money you save by making your own gifts can be used to pay for the upgraded cutter....
As far as a 12" or 15" cutter, it will suffice but you will waste material with some designs.....Having the option to use 20" material often saves you money.....If you cut a lot, the money you save on material will pay for the upgraded cutter.....
Plus even if you do not plan on doing signs or wall vinyl, you will from time to time...Our family and friends often get cut vinyl items as gifts....The money you save by making your own gifts can be used to pay for the upgraded cutter....