the U.S. race market is split between the TRIone, and the Snowglide. these both work extremely well, and there are pros and cons to each. price is about the same for each. I do not feel that there is a clear best choice between those two. We own and use the Snowglide at our shop. We have had many podiums in the Tahoe area with athletes on skis prepped with the Snowglide. We chose the Snowglide because the ski sits base up, and it is ergonomically easier to keep the device clean on the edge.
I have talked to a parent of a top level collegiate athlete that is using a portable battery operated unit that is distributed by wintersteiger that is considerably cheaper, but i have no personal experience. it looks difficult to control as the ski is up on edge. also the cutting stone looks suspect.
the unit you are talking about that uses a dremel tool looks like junk. it is advertised on ski racing online. and based on the video clip, i am guessing that you will be very disappointed with the end result. when you see either the TRIone or the Snowglide up close and then look at the lack of precision in a dremel tool, you will understand why i am concerned. the discs for the TRIone or the Snowglide cost more than 6 complete dremel tools. if you put the stone that they ship with that device on you edges, you will absolutely deserve the result that you get.
one word of caution to any of you considering these options is the danger to your health using these machines. they put off a very fine cloud of metal dust that can be breathed into your lungs. there has been a few WC techs that have experienced issues with this dust getting into their lungs. eye protection and a respirator is mandatory as well as some type of magnets on the tool or on the edge of your bench below your vice are needed to pull the dust out of the air.
just for the record the benefits of machines is speed and work reduction if you have many skis that need to be done in a short period of time. there are still many WC techs (especially in SG and DH) that still use hand files. for an individual masters racer, doing only your own skis, you will find that by the time you set up the machine, you could have touched up your skis with a file.