The Quickie: go see it. It's funny, if not hilarious. I can't imagine anyone not liking the movie, even though it doesn't have the serious side (depth?) that it could have had. (Many won't mind this part at all.)
Synopsis: Michael Keaton plays Doug, a guy that just doesn't have enough time to do everything he wants (or needs) to do, so he gets himself cloned... and then again...and again... and again. The movie was done by Harold Ramis, who did Groundhog Day and Splash (remember Daryl Hannah's debut movie about the mermaid?). (I'm sure Ramis has done other movies, but I can't remember.) Andie MacDowell, who plays Doug's wife, Laura, was also in Groundhog Day but is better known for her role in Four Weddings and a Funeral.
Pros: Michael Keaton steals the movie, hands down, and is the primary reason why the movie is worth seeing. The movie has other good points too; the concept is good, the special effects (of the interactions of michael keaton with his clones) are top notch, and the script is packed with one-liners with great physical comedy.
Cons: there were a couple of moments where there was strong potential for emotional moments or depth of character that never really surfaced. While those moments never arose, I credit the movie for not turning cheesy or sappy -- that sinking feeling you get when you're the victim of "formula" scripting. But, it's still a minor drawback that the movie really just avoided those opportunities where it could have had more depth or thoughtful moments. Wouldn't you sit down and have a discussion with yourself if you could? Just a little one? I think a one or two-minute conversation early on could have implied that it did happen, and may have happened off-camera sometime. That, or something like it (like more depth in Laura's character) would have also added some depth to the plot or just the movie in general.
Commentary: Keanton is cloned 3 times, the first retains mostly the testosterone, the second represents his more "feminine" side, and the third is... well, a retard. Keaton does a great job at each of these personas. In that light, it does an acceptable job at avoiding obvious questions, stupid characters or silly or contrived situations just to support a gimmick. You don't really think about how "cloning" works...or why an average construction worker like Doug can get cloned, or how is it being kept from everyone else, like the media. And if there are clones of you everywhere, how is it that few people notice this (like IRS people when more than one SS number is used in employment)? I say the movie does an "acceptable" job at this because it does a good job at keeping your attention focused on the situations and on Keaton's talents. You willingly discard the obvious logistical problems associated with having neighbors or grocery clerks take notice.
The movie doesn't try to be anything other than a Keaton comedy, but you can't help but notice the stronger potential that wasn't tapped. If Keaton hadn't been so good, I'd have considered the lack of depth to be lightly more of a problem with the movie.
In closing, I loved Groundhog Day, and strongly recommend it as a
video rental if you haven't seen it. The movies are similar in
structure and in the basic concept that a "miracle" event happens
to someone early in the movie, and the bulk of the movie is a
series of comedies and errors where the main character goes through a
personal transformation, at which point, the premise of the movie
"resolves" in a subtle, gentle way. In that respect, _GD_ is better
than _M_. However, Michael Keaton's comedy in _M_ is so different
from Bill Murray's in _GD_ that the comedic aspect of each cannot
be compared to one another. Keaton is definitely hilarious, and
Murray was funny, but in his own way.