Halo laser as good or better than CO2 Fraxel laser?

Is Halo laser better than CO2 fraxel laser? I've read that CO2 can and does kill precancerous skin cells and does actually help skin cancer cells and destroying those skin cells when diagnosed with it. Does halo laser do the same thing or is that just CO2? Should you do a series of halo or do it only once every year or every 2-3 years as upkeep? Does halo help lift skin and what are all other benefits that come from it? How long to avoid all sun after treatment and how long with healing time?