What is a better laser for the neck Skin Tyte or Themi smooth?

I do not have personal experience in Skin Tyte broadband light source to deliver infrared energy to the dermis to tighten the tissues.  I have a significant experience with external radiofrequency energy such as: Thermage, Pelleve and ThermiSmooth / ThermiTight as well as ultrasound ( Ultherapy ).  The theory is that dermal collagen is improved when the dermis is heated to a critical temperature.  I am not aware of studies that compared both devices, the Skin Tyte and ThermiSmooth.  The result is not expected immediately, as new collagen is produced for at least six months after the procedure is done.

Actually neither Thermi Smooth or Skin Tyte is a laser; Thermi Smooth uses radiofrequency (RF), and Skin Tyte uses infrared light. The idea with all of these types of treatments is to place heat under the skin sufficient to stimulate a healing response with collagen remodeling. There is some evidence (unpublished study that I did a few years ago) that applying RF immediately after liposuction enhances the degree of skin shrinkage. My preference now is to use Ultherapy, which employs focused ultrasound for more precision.