Great review! The pics you included should be in the manual. Although the US version is much better than the original UK manual, especially for the initial set up.
I first heard of the Sweetspot about a month ago when SkiA became of sponsor of another ski forum as part of a move into the US market. Very glad they are a sponsor for TSD too. Given what I learned last summer about the importance of improving proprioception by doing balance exercises for knee injury rehab, I didn't hesitate to order. SkiA customer service is certainly good. The company was quick to respond to my email questions. They sent a PDF file version of the US manual even before I ordered. Also refunded the shipping fee as a goodwill gesture because delivery took a bit longer from the UK. They will be shipping from somewhere in the US soon.
I got my package last week. Decided to use my old boots for training purposes. I was still using them for skiing at Massanutten last season. Since they are softer flex and have a walk feature, makes them a bit easier to get on and off. I figure that makes it more likely I'll do Sweetspot exercises more often. My current boots are the same brand so the fit is not much different. Later on I may use the Sweetspot with them, at least to see if it makes any difference.
I've only used the Sweetspot a few times. Once set up is complete, you have to re-attach the Sweetspot every time after putting on the boots. The quick release makes that fairly simple.
There are four exercises: Centered (Centred) Balance, Movement (up & down) in Balance, Rotation Movements, Edging Movements. As shown in the SkiDiva's blog review, there are four sets of blocks going from Green to Black going from about 2.5 inches to 0.5 inch. I'm taking it slow. The suggestion in the manual is to "excel" on a level before proceeding to the next. On Green, I can stand still (natural flex of my boots), move up & down (crouch and touch toes), and tilt as if putting skis on edge, all without losing balance. Rotation is more difficult. Plus I need to figure out the best surface to stand on for rotation that doesn't mess up the blocks or our floor.
The instructions in the manual are to do an exercise for a bit, then take off the Sweetspot and stand for a bit without them, then repeat a few times. The questions you are supposed to ask yourself immediately after the Centered Balance exercise are:
* Do I understand where the balance points are?
* Can I feel the balance points under my feet?
* Did my balancing on the trainers improve during the session?
Ideally, you are supposed to use the Sweetspot for an exercise, then do a related drill on skis until you feel the same balance during a drill before moving on to the next Sweetspot exercise. Needless to say, that's not how I'm going to do it since I'm not at a ski hill and don't want to wait. I certainly could feel a variety of muscles working while using the Sweetspot, especially my glutes when doing Movement in Balance since that's essentially doing squats with something extra.
One thing that isn't obvious until you see the blocks is that they aren't completely flat on the bottom. They are slightly curved. That's deliberate to make edging movements safer to do.
One thing for sure, doing the edging movements in ski boots makes me feel that much more confident that skiing without an ACL will be no problem. Had done the same tilting motion on the Skiers Edge II, but not in ski boots and not as much of an angle.