PicoWay, PicoPlus and Picosure lasers are different brands of laser where lasers are delivered in a much shorter time (i.e. picosecond rather than the nanoseconds) that Q switch lasers deliver it. The claim to these lasers is that with shorter burst of pulse, it will theoretically means less thermal damage to the surrounding skin. Some of these companies also claim that that also means it can deliver more energy and therefore is more effective.
The truth is that there is no real strong head to head studies to show that picosecond laser is better than the conventional Q switch lasers in pigmentation reduction. Q switch laser has been around for several decades and picosecond lasers are a new trend with lots of marketing campaigns done on the internet. More recently, there is a ongoing lawsuit against PicoSure laser and its harm.
I think the important point I want to make is that it is hard to know the difference between what is marketing dollars talking and what is real evidence based medicine. Many studies have small sample size and are sponsored by the product company itself. So are many claims on the internet.
My personal opinion is that many pico lasers used in the hands of the right doctor will function very much like the conventional Q switch lasers if the power, duration and diagnosis of your pigmentation is correct and the aftercare from the doctor is followed. I am honestly doubtful about claims of significant superiority to Q switch lasers in pigmentation removal. In fact doctors thinking that such picosecond lasers are much safer and therefore increase the power wrongly may result is greater damage than good.
In short, go to a doctor who is experienced in pigmentation reduction rather than focusing so much on what laser is being used.
Hope that helps.