This device is made for tracking Astro objects, sun and moon etc where you can use your camera + lens of your desire. So, it is more flexible in terms of what equipment you can use, e.g. different lenses, from wide to telephoto.
While the ZWO Seestar S50 PRO is more of an all-in-one-solution (a highly fun one, from other people to judge, especially first amateurs). The Seestar S50 Pro is based on so called Smart Telescopes (with built-in 8 MP sensor), and two lenses of which one is an APO corrected 250 mm ƒ5.2 lens with 4 elements, and the other smaller one i believe a 50mm ƒ1.7 lens for Milky way Panorama shots. Since the device uses multi-shots, you are not limited to the original focal length, really, but can choose to cover a larger area.
Star Adventurer GTi Pro
With this Astro tracker, I can for example use ANY camera as well ANY lens for astronomical photography - up to 5 kilo (in real life, I assume the limit is more like 3.5 to 4 kilo). In other words good enough for most of my lenses - even the big Fujifilm GFX cameras would fit, including the 500mm lens which is "only" 1.3 kilo alone.
Star Adventurer GTi Pro
ASTRO TACKER VIDEOS
Collection of explaining Videos
People made a couple of videos explaining who a star tracker works - in this case, the Sky Watcher Star Adventurer GTi Pro, some even go into the finer details.
