Between Fractional, CO2, and Genesis Cutera lasers, which procedure is more effective?

For brown spots and acne, the Picosure laser is the best treatment for asians. Out of all the three you listed, it will best do the job including treating brown spots without risk of hyperpigmentation. This is what I would offer to my Asian patients.

Fractional laser is an amazing and highly effective treatment in our office. We use the laser treatment to help with acne scars, large pores, fine wrinkles, tissue collagen loss, scars, sebaceous hyperplasia, active acne, and for brightening dark pigmentation. Although there are very strong fractional lasers such as CO2 laser, we use lighter treatments for corrective skincare and maintenance of results. Our Thulium fractional laser, clear and brilliant laser, and Ultra Thulium laser are excellent options in our clinic. We also perform CO2 fractional and erbium depending on skin tone and tolerance for downtime. Patients do have to use a Melarase cream before and after treatment to help further reduce pigmentation after laser. Melarase AM, Melarase PM, and Melapads can seriously improve surface sun damage and UV related pigmentation. Dark spots can improve with these treatments. I recommend fractional laser for incisional scars as well, especially after plastic surgery.
Best,
Dr. Karamanoukian
Realself100 Surgeon

An ablative CO2 treatment properly performed is going to produce the most dramatic skin tightening and smoothing. However, given your skin type a fractional CO2 treatment would be the best option.