On the side effects issue, generally there are no long term problems.  Certainly there can be some temporary redness, dryness, pigmentary changes, etc for a few days to, in some cases, even a few months.  Long term side effects are very unusual but I never say never because we are all individuals and can have very individual reactions sometimes.  The fractional CO2 lasers take longer to heal than the Fraxel Restore (fractional erbium) for example.

 As far as results, nothing and I will say it even louder :) NOTHING is permanent!  Facelifts aren't permanent, lasers aren't permanent, etc.  Everything in life, including our aging process, changes.   But you can get very nice results from a series of fractional  treatments like the Fraxel Restore for mild to moderate changes due to aging and sun.  If you have moderate to severe damage, the fractional CO2 laser may be more effective.   Plan on 1-2 maintenance treatments a year though with a fractional erbium (the gentler one) depending  how much you are outdoors. 

Hope this helps.    Dr. I