SpeedT4X: The round head of Tria is fairly small (diameter is a little under a ½") Each use can take a decent amount of time depending on the area you're working on.
S.S.: The rectangular head of the system is very large (about 1" x 1 ¼") so treatments are very fast. Both of my entire legs were done in ½ hour and both underarms in less than five minutes.
Ease of UseT4X: Fits in the hand nicely and is very easy to operate. The cordless feature does allow you to twist and turn the device very easily. But if you're in the middle of a treatment you have to stop and wait for it to re-charge, remembering exactly where you left off.
S.S.: Cradles in hand and is very easy to use. It's not cordless, but that never seemed to be a hassle or a problem. In fact using it as long as you need without having to re-charge it is great. Temporary impressions lasting about 30 seconds from the head are made into the skin to let you know exactly where you've hit, so you can easily go to the next section without overlapping. You have to be careful to follow these lines exactly or you could end up missing hair.
Life and CostT4X: Retail price of $449 (buy direct). Tria Beauty Company points out it's capable of delivering up to 90,000 pulses. When it runs out, you would need to buy another device.
S.S.: The suggested retail price is $499 (buy direct). A lamp cartridge that comes with the system has a life of about 750 shots. "That should cover one treatment session for two legs, two arms, two underarms and bikini line for an average body size" according to the instructions booklet. Replacement lamp cartridges retail for $45 (less if bought in a 3 pack). Depending on the how many areas (and their size) you're treating, the company suggests you will need anywhere from one to seven disposable lamp cartridges in the first year.
ResultsT4X: The company claims it, "delivers up to 70% hair count reduction in just two treatments." Follow me through my experience and personal results staring with Testing Tria: Part I.
S.S.: The device is FDA cleared for permanent hair reduction. According to the Silk'n hair removal clinical study of 150 females using the hair removal system these were the average hair reduction results after 6 months "41% in the underarms, 54% on the legs, 43% in the bikini area and 52% on the arms." You can read about my results using Silk'n, starting in Part I.
If you have bought either device, please share with us which one and why in: Tria or Silk'n?