Not that I hated it or anything, just it was a very mediocre comedy. On my review scale, 5/10 is right down the middle of the road of mediocracy (I hate these places that pretty much only use 5-10 of the scale with 5 being absolutely dreadful and a movie has to get like 7 to be just average...sorry but 7 is above average, below average would be somewhere below 5).

But yea, it provides a few laughs, but in the end it's an average/forgettable movie that nobody will be talking about again soon enough (not like they still talk about The Hangover or Old School). I'd put this more in line with his School for Scoundrels.

Edit: I thought Planes, Trains and Automobiles was a very enjoyable and fun movie when I was younger (the last time I saw it).

I don't think it was anything like that for me. I could dealt with lack of originality if the movie had any character. But that was the thing, there never was any real character. The writing just wasn't that good and didn't allow for you to connect with the characters. There were plenty of one-liners that provided a nice laugh here and there. But there was no depth or substance to back all that up and give the movie that extra layer it needed.

For instance, in Planes/Trains the characters go through a character arc and you begin to sympathize with John Candy's character. The attempt to recreate this for Galifianakis' character falls short because any 'emotional' or 'heartfelt' scene that was meant to do that just felt contrived, thus it could draw you in like John Candy's sob story did in Planes/Trains. That's just one example where it was lacking that extra depth it needed. And it needed that extra depth/substance because ultimately it was going for that connection with the audience and the characters. Also, the comedy it the movie wasn't intelligent...rather juvenile and sophomoric really, and that type of comedy, while funny, can't hold up a movie all by itself (especially a movie that's try to take itself somewhat serious). So all the one-liners Downey and Zack could muster couldn't hold it up alone.