I'll formally introduce myself in a minute, but stumbled upon this by a google search and wanted to share some adventures I've had with these watches.
I purchased one with black dial and steel bracelet as a first, an excellent watch, since I own a Weishi Timegrapher 2000 I tested it and found out that it ran quite beautifully in all kinds of positions. Then I pulled the trigger on a white dial brown leather strap, this one had issues with what looked like gearing problems with the seconds hand, which moved around when changing the watch from several horizontal positions. So I contacted the seller, who was so friendly to send another one, but it had the same issue. I'm now guessing the black dial steel bracelet could be of a better batch and since they were on sale today I bought four of them. You could ask why so many? Well, I discovered the movement fits many other watches. What I found out from experience and the movement PDF that I'm thankful for which was posted in this thread:
1. the hands of an ETA fit
2. it has four dial pin screw positions that make it suitable for both DG2813/M8215 and ETA 2824/2836 dials, dials that have four pins actually fit with all four of them without the need to cut any of them
3. the canon length is quite short, but the Starking watches come with an extra thin spacer, also with four cut-outs to fit any kind of dial. Do watch out for thick dials for this reason, especially with thick markers.
4. the watch is about as cheap as most low beat movements in this category
5. The main spring has jewel bearings, so it has at least two more jewels as a DG2813
6. The date flip transition takes about a quarter of an hour from starting to move to actually flicking over
7. The date wheel is a bit smaller than DG2813, so beware
8. DG2813 or ETA date wheels don't fit as they're too thick, especially since the short canon.
9. the movement is 99% based upon a DG2813, but different enough to not fit the high beat parts. At least I didn't succeed to make a swap there, and made two attempts. I couldn't figure out why yet, checked all the parts under the magnifiers (Mantis and HD cams with macro lenses) I have.
I know it's by no means economically sensible to use it for the movement, as you'd be far better off with an ETA clone movement, but this movement and especially the way the first one runs (and still does after putting it back together) was somehow appealing. And on top of that I've only started the watchmaking hobby a few months ago and needed some target practise, and what better to use than some brand new and cheap victims haha!
My aim still is to shoehorn this movement in to a Black Bay hommage. I did already find out that the Corgeut dials the sell on .........s have the same date windowdistance and the size is fine for the font, and I wanted to pair that with a snowflake hands set, a sapphire glass Black Bay homage case, and a leather suiting strap. These watches are sold complete on Aiexpress from Corgeut and Parnis. The latter has a 24J 9015 option, and I already own one of those (yes Black Bay fan here...) and it is a superb watch, incredible finishing and that 9015 runs spot on. Then Parnis has the 21J with 8215 in it, but I dislike the 8215 for not being hackable. I did make a hands swap on that 24J Parnis, because they are stock fitted with mercedes hands. The Corgeut watches already have snowflakes, and look great, and the name appeals more to me, but from having ordered a case earlier on I noticed the finishing is not at the level of the Parnis in many ways.