This was my main practice for about 6-8 months prior to joining this community, and it's been really awesome to see people take to Zhan Zhuang over the years. It informed my subsequent practice of TMI significantly in having developed a strong sense of the body and energy, and it's why my experience of body-breathing was so fruitful early on. To reiterate, it's an intensive physical exercise and a great meditation practice, so if one is tight on time this is a good way to address both needs simultaneously. To address some of what /u/oscarafone said:

It may be useful for dealing with energy blockages

I'm not sure what they're referring to as energy blockages, but the whole aim of ZZ is to get the energy system flowing smoothly. Traditional Chinese Medicine asserts that smooth energy flow in the body is synonymous with good health, hence acupuncture, taijiquan, and Qigong working with the various meridians to address blockages.

Practitioners sometimes say that it "builds" energy as opposed to traditional exercise which "depletes" it

When one finishes a good session of ZZ, a sense of well being, liveliness, etc., is predictable result. Compare this to something aerobic like running, weight lifting, etc., where one feels depleted and tired afterward, this is the line of thinking that comes to mind in considering the quote above.

At the same time they say it releases tension instead of generating it

For those taking the practice on initially and for some time to come, there will be tension from not holding the posture well. What eventually occurs is that one's mind holds the posture without wavering and the body is unable to hold the tension: it then relaxes within the posture and becomes much easier to hold, even effortless.

It's been great to see /u/duffstoic and /u/turtlescarf43 keep this practice up for quite some time now, as they've inspired me over the last year to reconsider it as a daily practice. I opted from some of the core exercises from The Art of Chi Kung for time's sake, but here I am, re-inspired!