I have used the Concept Air 4.5 Smart Kite quite a bit over the last couple of winters. I like it so much I thought others might be interested. Where I kite is on a frozen lake and while it is snow covered most of the time it is very exposed to the wind and do not get a lot of deep powder. Most of the time it is like today where I am on untracked snow and my skiis are sinking in no more than a few inches. So there is not a lot of drag most of the time.
The 4.5 flies in quite light winds without stalling if depowered. So I suspect it would make a good trainer kite in light winds. It turns well depowered just slower than when sheeted in. Sheeted in it almost pivots on the spot if turned hard. So you can choose the radius of your turns easily. Even though it turns quickly if you want it does not race across the wind window, although in very high winds it obviously speeds up when sheeted out after the turn. It is very stable and I can take my hands off the bar while putting my skiis and gloves on. The kite will not stay overhead but will move slowly to one side giving you time to do things before grabbing the bar and re-directing it up.
The depower is very large. Today I was kiting with it in winds of about 15 to 18 knots and having a good time. Everything was easy and smooth and the powered delivery was gradual rather than harsh. In those winds one dive and I can park the kite and cruise slowly upwind. Working the kite
and moving at right angles to the wind generated lots of speed. Once I am moving quite fast sheeting out allows me to easily head upwind. I have had the kite out in over 30 knots with no problems at all. I have no idea what the top end wind range would be as much windier than than I go to a smaller kite as I find that more fun.
Launching and landing are very easy. As an open cell kite I just lay it out at the edge of the window and sheet out and go. Even landing in over 30 knots is simple, just pull on the strap connecting the rear lines and down it goes and sits with minimal pull or moving about. I then wind a couple over rear lines on the bar first and then wind the lines up to the kite. Very easy and I find quite safe.
The thing I really like is that kite drifts really well so that once I work my way upwind I can do repeated turns towards the kite and it just drifts back with minimal pulls until redirected to generate some power. Obviously you cannot race towards the kite at high speed multiple times or the lines will go slack.
The kite handles gusts great. That is why I have it as it is usually very gusty when it is windy here. There is minimal surging and falling back in the gusts and there is controllable power in the small surges that do occur.
So what do I not like about the kite? The chicken loop safety release could be be easier to grab in big mitts, although it works fine. Other than that I really like the kite. Diving the kite to generate power seems to generate less power than my other brands of kites. So if you are aggressively working the kite to generate speed and power you might be a bit disappointed. That is what also makes is easy to use and safer in higher winds if you make a mistake.
I am not associated with Concept Air and I pay for my kites. I started buying from them back in 1999 and have found them great to deal with. I also use them to mountain board on beaches and they are also great there as well.