You are talking to the Shape Cut advocate of the century! I love, love, love it. I started out with the smaller one, and then bought the bigger one. The bigger one gets more cuts, and I love it. It is rather harder to handle since it is so big, but it is the one I'd recommend. You might also think about investing the in the June Tailor Half and Quarter Square Triangle ruler to get perfect HST all the time. It is another ruler I love dearly. I also use it to square up from 1.5 to 6.5 inch plain patches.