I have the Alto cutting system and I love it. That said, it sits on a "cutting table" and is never moved -- it would be bulky to have to move and store.
I haven't used the adjustable arm to cut angled pieces, I primarily use it for cutting strips and squares, and I use the lines on the background to cut triangles. I will say, though, that it has given me the ability to cut straight and easily and has improved my quilting dramatically -- I couldn't do what I do without it!