I thought it took up a lot of real estate for what it was. I also wasn't that impressed with it's 'lagoon' toolbar.
If you're expecting any kind of conventional drawing package features such as shapes etc. I suppose this is good provided you are ONLY sketching and don't ever want to change the color (or line thickness etc) after you've lifted the pen and seen what you've got. I also had the desire to drop down some text on my freehand technical drawing sketch but there is no way to enter text! I get that it'll be converted to pixels and not editable afterwards, but still.
There is a way to draw ovals, but it's pretty obtuse and no other kind of shape at all is supported. you can't change the color! As previously reported in the MacUpdate reviews, there is no way to draw any kind of rectangle. I drew some random squiggle and then decided I wanted it to be a different color. However, I'm way frustrated at the lack of some bog-simple features. As far as scribbling and painting is concerned, this is an OK tool.
