I am wanting to do some type of laser on my neck, chest and arms. My dermatologist recommended PicoSure, 3 treatments?

PicoSure is quite literally "light years" ahead of other laser treatments. The latest in picosecond technology, the PicoSure delivers Fraxel-like results without the downtime and typically at a fraction of the cost. Also appreciated, the treatment is rather comfortable, and topical numbing is not required when using cryo cooling.
We have seen beautiful and long lasting results for patients seeking skin revitalization and rejuvenation with PicoSure. This includes an increase in collagen production, reduction of fine lines, wrinkles, and pore size, improvement in overall tone and texture, and clearance of pigmentation.
Three sessions is a very reasonable number of treatments for achieving optimal results. I would recommend spacing the sessions 6-8 weeks apart. Of course, as with any laser treatment, be sure to avoid sun exposure in the weeks leading up to and after your treatment. I believe if you loved your results with the YAG laser, you will truly be thrilled with your PicoSure results.

Hello and thank you for your question. Skin rejuvenation with the PicoSure Focus laser activate your body's natural skin cell processes for healthy, more youthful looking skin.  Focus treatments lighten unwanted pigment and stimulate the production of new collagen and elastin, without the pain or downtime of other treatments.  Treatments are usually 15 minutes or less with just a few hours of mild redness, which we refer to as "social downtime", versus several days of downtime with other laser procedures.  You will likely want a few treatments spaced a couple of weeks apart to achieve the results your desired results.  Our patients have been very happy with their results! 
All the best to you!

Thanks for your question.  Obviously the best way to answer your question is with an in office consultation.  Our recommendation would depend on your chief concerns.  We have been using the PicoSure FOCUS for almost 3 years and our patients are seeing excellent results correcting brown pigment and fine lines.  If you were a Skin Type I-III and were concerned with broken blood vessels (vascular lesions) & brown pigmentation, we might recommend a IPL PhotoFacial instead.  The PhotoFacial is great for color correction, but doesn't do anything for texture.  If texture was your main concern and you aren't worried about pigmentation, we would ramp up to a 1540nm like Fraxel or ICON to do fractional resurfacing.  Keep in mind that more intense/deeper treatments require more downtime, but you will need less treatments.  If you choose a short downtime treatment plan, you will need more treatments in the series.  The most gentle would be the PicoSure FOCUS treatment with almost no downtime.  It is safe for all skin types, but you would probably need 3 to 6 treatments.  Best of luck.