I like some things about Construct. It has plugins etc... for behaviors and things, making certain game types easier. For example, there is a platformer behavior which includes jumping, double jumping, and I'm not sure what else besides tile collision. There is also one for Top Down Shooter, and several others that can make things easier. Gamemaker doesn't include this kind of thing, though it is more than capable of doing them, you have to find one already done, a tutorial, or code it yourself.
Speaking of coding, I could never get into Construct's D&D coding. I know that it is much more powerful and capable than GM's D&D, but GML scripting seems more powerful and easier than Construct's D&D. And I for one coming from more of a coding background find GML scripting that much easier. On the other hand, someone with a different background may find Construct's D&D easier than GML scripting.