Should I Watch...

It's a very sweet anime. By sweet, I gues I mean it's heartwarming.
The romance develops slowly, I have to say. However, it's worth it.

Clannad is a story that does a great job at pulling the heart strings. Since the comedy isn't too blatant and so in your face, its tone is very light giving the show a chance to create a mood that gets your attention. The use of their background music doesn't draw to much attention to itself, but like everything else it does set the atmosphere. The voices in the music that they used compliments the scenes very well. Clannad doesn't screw around and stall to complete an episode. They take full advantage of the time they have to completely develop a character and create the story around the characters, filling the show with content rather than side-story. The stories are also very engaging usually dealing with the loss or disappearance of something important. It is a lot of built up tension with a satisfying resolution.

Watching them is the best course of action.
Sure, you can waste your time watching any other mainstream anime *cough* that are hundreds of episodes up -- no offense.
What makes Clannad different is that even though it's just a few episodes -- not really though -- they are able to achieve what most animes strive to attain, and that is to be remembered because of the emotions they invoke.
Given a choice of watching it or not, obviously, the former has more pros than cons imho.