When I was a kid I remember talking to my Brother (who is 7 years older than I am) about the Green Lantern. GL was one of my favorite characters at the time if for no other reason than all of the cool things I could think of doing with that ring. (Then again, just about any character my brother liked became an instant favorite.)
I don't even remember if I'd hit double digits in the age department, but my brother was explaining how Hal Jordan started as a test pilot and so he was a loose cannon compared to Super Man or Batman. As a test pilot he was either a daredevil or crazy. Possibly both.
We have to think of this movie as it stands alone - is it any good. However we also have to be ready to contrast it against all of the other comic book movies; we don't want them all to be the same. If they were all as stoic as Super Man, or broody and emo as Batman, the formula would get very stale indeed and the genre would once again become less relevant and marginalized by every reviewer except Movie Bob.
Without a doubt Tony Stark from the Iron Man movies is the first larger-than-life personality we've seen as a comic book icon in a movie that made a ton of cash. That doesn't mean Stark owns the "Hero with more personality than a broomstick" concept. That they've give Hal Jordan a lust for life, and is the kind of guy you'd see in a bar just about anywhere in the USA, is a good thing.
Hal can harden over time, and become the dark and brooding... green-light and brooding no-nonsense space cop over the next couple movies. It sure looks like they are setting us up for at least three movies.
Do the effects stink right now? Perhaps, but I thought the same thing about the Hulk before I saw it in the theater. Also, his suit looks really bad in still photos, chronically stupid to tell the truth, but I think it looks pretty good when in action. They just need to darken up his mask a bit.