So I am also just getting started out and I also decided to get some of the kits to work with. To all who think that these are just "soldering practice" and not educational, I would say that's a bit shortsighted. It depends on how you approach them. I set out to try to find kits to make some useful devices for getting started-- in the end I decided to get a power supply kit and the component tester kit. I'm still waiting on the power supply kit, but I built the component tester last night and you're right; it was certainly soldering practice.
But that's not all it was. As I said, I'm just getting started, and the whole experience can be a bit overwhelming when you're really getting started. The kits gave me a good starting point, with a fun path forwards that ended with a working device at the end. From the very process of choosing which kit to get, I learned an awful lot. Just as an example, when looking at critiques of the Bangood power supply, I learned about peak vs. RMS Voltage for AC, how to read datasheets of components, 78xx power regulators, linear vs. switching power supplies, and lots more in between. I think that qualifies as more than soldering practice.
So far, the kits have been a kind of guided tour along the path of basic electrical components. When I pick up a new part I don't recognize, I look it up before I solder it in. Even better, the most frustrating part was that it was hard to follow the PCB traces to really follow the full circuit, so I think I want to try another design, but this time do it on veroboard so I can really dig in to what each component does.
I'm sure for people with more experience, there wouldn't be much left to gain from these kits other than a relaxing, toy-building project. But remember, for those of us with a lot left to learn, there's plenty to be gained here.
Oh! And +1 on the component tester, but if you've never soldered SMD components (which I hadn't) to try to practice a bit first. Soldering the 3 SMD parts was the first steps in my kit, and unfortunately, also the trickiest. The instructions DO say you can skip the SMD IC if you want, but where's the fun in that?