What should I get, ThermiTight vs Profound Laser (under the skin)? (photo)

Thank you for your question and I understand your frustration. These two devices offer some similar benefits but they are not exactly the same. Profound is a radiofrequency microneedling device, which creates tiny channels in the skin to stimulate the body’s healing processes. This boosts collagen levels within the dermal structure, which in turn smooths and firms the skin’s surface. ThermiTight also uses radiofrequency energy, but delivers it via tiny probes inserted into the dermal tissue. These probes can penetrate more deeply than the microneedles to achieve a more dramatic effect. 
If you are looking for skin rejuvenation, Profound may be the best choice. The collagen produced throughout the treatment area reverses some of the aging signs and refreshes the appearance of the skin. ThermiTight is more focused on tightening the skin, constricting tissue for quick results and triggering collagen production for long-lasting improvement. As long as you are working with a board-certified dermatologist who is well-versed in these treatments and has a full understanding of your concerns and goals, you should be able to achieve a very good result. 

As we age the skin sags there is  nothing  you can do that but try preventative  energy-based or thread-based  treatments or get a neck/facelift earlier in the aging process.  There are numerous options and some can be used in combination to get best outcomes but you need a consultation with an expert.
Options include for skin tightening :
thermage radiofrequency to heat skin and tighten it over time and prevent the aging process
ultherapy highintensity ultrasound to contract muscle and tighten the face and neck and prevent the aging process
PDO nova threads or instalift threads for immediate lifting without surgery and long term collagen production
sculptra injections for collagen production to areas of the face and neck with crepe skin or early sagging
btl exilis ultra, venus legacy, thermi250 , or inmode forma/contoura  for constant collagen stimulation monthly with facials
facelift/necklift with fat grafting/fillers if you need a big improvement
ThermiRF or J plasma /Renuvion or Inmode FaceTite   internal heating and tightening to long term internal heating and tighting with or without surgery
Platysmaplasty to tighten the muscles of the neck long term and create contour
Facial implants or fillers to contour the jawline and chin to improve the apperance of the nec k
Fractora/Morphenus8 or Intensif microneedling RF for improve superficial tightening, neck and chest wrinkling and crepe skin 
You need to see an expert in facial sculpting and age prevention.  Best, Dr. Emer.