I would agree with the 7tm comments. (I don't have any issues with their performance though.)
I have a them and they have never released in the 5 odd years I have used them. Although I don't fall often. And if you do it is different from Alpine skiing as you tend to fall on your arse, mostly you can just push with your hand to get back up. Or straight over the front face plant which is more interesting.
Part of the reason I took up teli was a knackered knee. (Former Racer.)
The best thing for me is there is no or limited pressure or jarring on your knees as there is nothing to resist against. Your legs act like shock absorbers all the time. The light boots and light skis are great. Much better too as on steeper slopes you really need to move your feet quickly to do tight turns.
It is a bit like doing a load of lunges but as you don't really stay in the same position as your legs change position constantly.
It is considerably more energetic and tiring than alpine skiing.
But if you are too knackered just stand up. I have no difficulty at all doing regular stand up skiing in Teli gear.
Some tips for teli skiing. Keep switching your stance. Don't think of single turns, it is a rhythm of switch switch switch. Wide or tight turns same applies. The least stable position is when you are standing like an alpine skier. Quiet upper body, (shoulders) facing the fall line all the time, exactly the same as alpine. Although you may well wave your arms about for balance if going fast. And there is quite a lot of twist in your shoulders on steeper slopes.
Get low, I often see people switching from Alpine skiing with the good new Teli gear. They don't bend enough or forward enough.
Get rid of your poles, you don't need them. (Or hold them in the middle.) Improves balance and less to worry about. In my opinion pole planting is not really very important in teli skiing.
Save energy. Easy wide turns on the less demanding areas. Shuffle, stay low and slide your feed for turns rather than so much up and down.
Teli is a bit different from alpine skiing as you can do both carved or drift turns. Like someone else said more like snow boarding in feel.
You can control your speed on steeper stuff by deliberately sliding in the turns.
Impressed with the video of teli going backwards. Will need to give that a go.