This is my personal experience:
I do it as a part of preparatory poses for yoga. I get into the posture and hold for a certain number of slightly deeper than normal breaths (2-3 seems enough). I also do the "knee-to-forehead" and "leg extended" postures in between (in yoga this practice is called "nadi vibhajan", I'm sure you can find some videos online), held for the same number of breaths. After 3 cycles of this, my spine feels much stronger and more mobile.
I've done the continuous flow before, but staying in the postures feels better to me from a purely physical, spinal stability and strength perspective - especially the poses I mentioned. There are other benefits as well - it definitely calms down the mind, which is one aspect of why it is done before other yoga practices.