The most "autonomous" watch I have ever worn. Solar charging, it essentially doesn't need a battery change and doesn't even require time adjustment, as it automatically synchronizes with radio signals. I live in the center of Athens and it synchronizes every night around 4-5. Very comfortable on the wrist, you forget you're wearing it; on my 18 cm wrist, it doesn't look big but neither small.
The watch is made in Japan and as it says on their site https://gshock.casio.com/intl/products/collection/origin/gw-5000u/ which they call ORIGIN, it comes from the original model of 1983. It has a much better and clearer display; the ghosting of the LCD is less noticeable than the others. It is stainless steel with a stainless steel screw-down case back and a better and softer plastic strap. Of course, it has an upgraded mechanism that finally allows you to set the date as we are used to, that is, DD/MM, and also to show the time while using the stopwatch or countdown timer, and of course the ability to light up automatically with the rotation of the wrist.
On the downside, the countdown timer and the five alarms it has are practically useless since they are hardly audible unless you have the watch next to your ear.

The ultimate "square" for fans of the most authentic G-Shock. The watch you buy if you already have other models from the 5600 series and it surpasses them all. It doesn't stand out or scream on the outside, but it differs on the inside. Discreet on the outside, without flashy colors, and made of synthetic resin, but internally, the case is made of steel with a black glossy Diamond-Like Carbon (DLC) coating and a screw back. The strap looks like the others (and is more affordable), but it is much more flexible and soft to the touch. It features the updated Module 3495, which is the same mechanism as the GW-M5610U, meaning it has a rechargeable solar battery and automatic time adjustment (depending on the region), with clearer digits and display. At the same time, it has a new (worse) white LED backlight that replaced the wonderful Electroluminescent backlight found in the basic and reliable DW-5600E. One of the few Made in Japan Casio watches, as it belongs to the "elite" with their very expensive models. Initially intended only for the Japanese market, some watches eventually found their way to Europe. If you are a fan of classic, historical, timeless G-Shock watches (and therefore knowledgeable about their history), a collector, or simply want to give a relatively expensive gift to someone or even better, to yourself, buy it - while it's still available!

The U versions are significantly upgraded.
For me, it fits perfectly in my hand, I don't feel it at all, the strap is soft and comfortable. I am 1.90m tall and relatively fit, and I have no problem with the fit on my wrist. Also, because it is small, I can easily wear it with a shirt.
Even though I am 45 years old with 1.5 degrees of presbyopia, I can see the time and date clearly.
It is solar-powered, so battery is not an issue. Based on other Casio solar watches, I don't think I will ever have to deal with the battery.
The automatic time update works flawlessly from the first moment.
Perhaps for some people, the price may be prohibitive, but for me, because I really like this watch style and combined with the solar charging and automatic time update, as well as the excellent build quality, I bought it as soon as it became available. Maybe the price will drop over time.
Now, regarding the durability of the watch in tough conditions/water, I haven't tested it except when I wash it under the faucet, when it gets wet from sweat, or if it gets dirty from dirt during gardening work.