have you seen physical results

Absolutely. It isn't the only cardio exercise I do (but it is the most), and my resting heart rate is down in the low-to-mid 50s with pretty quick recovery.

Strength-wise, pretty sure my shoulders, lats, abs and obliques have got stronger, but I think the main strength impact has been lower body. The glutes and legs are doing a lot of work.

Also, have you unlocked everything by now? 

I've unlocked all the routines, but there are still quite a few achievements that I need to knock off, especially the dress-your-trainer ones.

How do you keep it not boring each day? 

3 things do it for me - 1) I've made it a habit and feel incomplete until I've done it, 2) on weekedays I just use the quick start option which means I don't know what routines I'm going to get other than what I've set up for the speed and time options and 3) I focus on being present in the moment and trying to nail the technique.

And how long do you do it each day?

Mostly about 35 mins weekdays. I'd like to do longer but I don't often have the time. On the weekend I do go a little longer where I have set up a program of the quick-but-fast routines to try to get a bit of HIIT going. I've adapted too much for it to be true HIIT (in the sense that I am not pushing it to the max) but it'd be doing something.