Is worth it to replace only front and rear speakers?

[tealio]

I have had a full system before, but with my sedan that has the integrated sound system I want to stay as simple as possible.

Would anyone have any opinion on if it would even be worth it to just change out the front and rear speakers and leave everything else stock?

I know it won't make that much difference, I am just looking for a little better sound and the longevity of aftermarket speakers, since I'm sure the paper stock ones won't be bumpin for long.

Also, does anyone that has already replaced their speakers noticed what ohm and power handling the stock ones say on them? I would like to know so I don't buy too nice of speakers that wouldn't even be powered by the stock head unit.

Thanks!!