Hit the chords clean or keep to timing?

My suggestion is to slow down the whole song to the speed of your slowest chord change.  Practice it with consistent timing throughout, even though it will be slower than the "right" way (meaning the recorded version).  Get the chord changes clean and neat and ringing true.  Speed will come.  If all you have is speed, you will never get clean.  You need to practice that precision.  If it's just one chord change in particular that vexes you, then practice that chord change only play the first chord then change to the second chord.  Or if there's a particular passage, then play just that passage.  Do it slowly and correctly.  Practice just that piece 100 times per night.  By the third night, you'll notice a HUGE improvement.  Then work it into the song - still going slowly.  Do that a few (dozen) times per night.  By the end of the second week, you'll have it sounding pretty good and you'll have learned yet another chord change down cold that you can use in any song with that change. 

For what it's worth. 

- Zurf

Zurf's right. Slow the tune down if you need to but you must play with a regular predictable rhythm. If a chord change does not go well, be on time for the next one. Lay in wait for the problem chord and nail it next time around.

Thanks to chordie I learned  that sometimes while changing chords it is ok to hit the strings open in between the chords you are changing to and from.This buys you a little time and actually sounds good on some songs.