For face rejuvenation, does anyone know what's the difference between fraxel & pixel laser tretments?

Very similar: Fraxel and pixel are both fractional laser treatments ( co2 or erbium/yag) by different manufacturers. This is similar to asking the difference between coke and pepsi, or ford and chevy. The important factor is not the machine, but the skill and experience of the operator. Ask for credentials, experience, and see lots of before and after photographs. Neither is better; the surgeon is the key!

Fraxel and pixel: There is a difference . Fraxel penetrate into the dermis to cause collagen contraction. It may be a bit painful. Pixel may be less painful.