Love it, but sadly the sum of the parts is not greater than the whole

This movie gets a bid of bad rap. Understandable for the movie as a whole, but that doesn't mean there isn't still plenty of good stuff to be enjoyed.

Yes, the movie definitely feels like it needed a few more weeks in the editing suite, it ends too abruptly, and it seem that some key moments in the characters' story arcs are missing.
The plot is not wholly original, but still amusing enough to support a light comedy.

For me, the strength in this movie lies in some of the great performances which I just can't fault. Frank Whaley is brilliant and very entertaining, and there's some cracking supporting roles from the likes of John Candy, Barry Corbin and William Forsythe.
Funnily enough, the weakest performance seems to come from the only (future) Oscar winner in the cast, Jennifer Connelly. It's too hard to really relate to her, perhaps it is because she is painfully beautiful and almost doesn't seem real or at least not to be in the same league and world as Frank Whaley's character and us mere mortals. And I suppose that's also the point, she is the unattainable dream girl.
Many have said that many of her scenes seem to gratuitously exploit her physique, and while not entirely untrue, it's still pretty tame in comparison to many other similar roles and does fit the plot and character, mostly.

Perhaps if John Hughes had directed this, and let the actors ad lib an develop and get into their characters more, like he tended to do, he might have pulled a bit more out of the story. I'd like to think he'd also made sure it was edited a bit better to allow for the story to be told more solidly. The ending is jarring without a bit of a final monologue or other form of introspection from the characters to summarise, whether explicitly or more subtly, their development over the course of the movie.

At the end of the day, as with music, whether you like it is all subjective. As with many guilty pleasures, I can see the flaws of this movie, and I can't really defend it, but nevertheless love this movie.