I received from my wife as a birthday present this past fall one of their system 4 big mountain series machines with the RPM plate, and love the machine! A very well made, very good actual ski muscle training device, and quite an aerobic workout to boot. I definately noticed this past season a few distinct differences in my conditioning after using the machine. First off this past fall with an almost 2 year old in my house and a very pregnant wife, my free time to go for long runs outside was greatly decreased, so the vast majority of my pre-season conditioning was done late night watching TV on my skier's edge. I noticed when I finally got on snow this year a few things different than normal early snow days for me. First off, even though I didn't mentaly think I was as aerobically conditioned as in years past (normally I'll run 2 to 3 half marathons in the fall at a 1:45 pace, but this past fall I'd of been lucky to get to the finishline of a 10k due to very limited training time), I was just as aerobically fit as I normally would have been. Secondly, those "ski muscles" that tend to get fatigued rather quickly those first few days on the hill, never did, and even the day after was without any muscle soreness
The machine does give you a very good similution of the modern technique with your feet shoulder width apart and the need to ski with your lower body as opposed to your upper body, and if you can handle 30 minutes non stop at anything level 5 or higher maintaining an average of 65-70 "turns" a minute, you'll be amazed at how good of a workout you'll get.
Great machine, IMHO worth the high cost, fun to use, and if you order a new machine directly from the company, their customer service is first rate!