Considering how different the OB4 system is from what I was using it is hard to know where to start.
The Semi Soft boots feel good. I was worried that they were going to be too stiff laterally. That turned out to not be true at all. The lateral stiffness feels about perfect.
What is very interesting is how firmly held my foot is. In most bindings the bottom of your foot moves a bit. Not enough to notice but it moves around. In these boots my feet are held flat and still in the boot. I think that is a good thing.
The hardware offers infinite binding adjust forward and backwards and boot angle. Because the boot holds my foot so positively I might end up with less rear boot angle.
The toe of the back boot had to be trimmed so I could get my feet close together. @mmosley899
warned me about this. It was easy. I just used a hack saw and trimmed back the front of the boot until I got it where I wanted. I need to go back and make it look prettier next weekend. Bottom line is my back toes about touch my front boot. The hardware makes this easy.
As I expected the first ride was a mess. I am not 100% sure why but I had to move my bindings back a 1/4 inch. (could just be how I measured it) After I moved the bindings back I was about 95 % on the second ride. Considering how different the boots are this is pretty good the second ride.
As for the release => there is a lot to learn but in the end you screw it on your ski, set the release setting and go ski. Simple is good. I don't crash very often so I can't say much else.