This is a great book, more or less. Thor has this strange ability to captivate me, with this idea that there are these strange Asgardian political factors that get in Thor's way, when he likes Earth.
Thor's girlfriend (well, more girl that he loves but doesn't want to settle down with at all, not even hug), Sif, shows up. That's probably my favorite part. They go on adventures together, and their relationship affects the way he battles.
The individual issues are hit or miss. There are some awesome things in here: the first story, where trolls stage a coup against Odin, was incredible. It was just battle and weird setbacks, very quick read. I also liked the RIngmaster and his gang of criminal carnies, they're always kind of unintentionally creepy and interesting.
But Stan Lee, bless his world reknowned writing prowess, kind of stinks sometimes. And here it shows from time to time. There's a few issues that are entirely Thor/Odin saying "OMG, something bad is going to happen", and then it's "NEXT ISSUE" before the battle. A lot of pontificating. Thor must've said "Nay, thou art battling with the power of Thor, the immmortal..., etc." like 1,000 times. It gets annoying. You want to see him struggle, not ramble in mid-battle.
The Adam Warlock thing was kind of cool (they call him "Him", but that's him....him), and Galactus was ok, also filled up a lot of those lame "battle portending issues" I mentioned tho.
Jack Kirby's art seems to work on mythological figures (in fact, he created a lot them for himself to draw, throughout his career). His faces get a little flat and weird occasionally.
All in all, a solid albeit frustrating read.