Yes: why would you want a keyboard that makes you squiggle to insert double letters when it's perfectly possible (as demonstrated by ShapeWriter and SlideIt) just to add the double letters as part of the normal recognition/correction process?
ShapeWriter, BTW, lets you do the after-the-fact substitution without having to hit an extra key like the Swype key you mentioned above. Just move the cursor to the word and the alternatives pop up.
I'm not seriously weighing in on the Swype vs ShapeWriter question; I started using ShapeWriter before Swype was legally available and have been happy enough that I haven't actually tried Swype, so I can't legitimately express a comparative opinion. But ShapeWriter's accuracy has definitely improved over the last few updates; anyone who had problems with accuracy a while ago but hasn't tried it recently might want to give it another shot.