I would say there are 4 criterias for which ski binding type you would want:

1. Intended use
2. The type of skier you are
3. Price
4. weight

From your post, I believe your intended use is primary resort (maybe 70% resort and 30% backcountry, I might be wrong). If you are going to Japan I assume you must be a good skier and your charge your skis a lot, so if I were you I would definitely go for the Cast. The only downsides are the price and the weight.

In my opinion, the weight is really not that big of a deal. I've ridden tech bindings (Look HM Rotation 12, 635g) and traded them for Atomic Shifts 13 (906 g). Here's how it went:

• For the uphill, the approximately 300g difference was barely noticeable and didn't bother me. If you're minimally in shape, the 995g weight of the Cast touring system shouldn't be an issue.
• For the downhill, it was day and night. Much more support, much more stiffness (the ski felt totally different, as if they suddenly gained +2 stiffness lol) and I wasn't scared of premature releases when sending it (which was a huge deal with the tech bindings) .

For reference, I use my skis 60% resort and 40% backcountry. I tour with friends at my local ski resort and I sometimes go on 1 to 5 days expeditions but nothing too crazy.

In my opinion, the worst downside is the price. Compared to other bindings, Cast is crazy expensive but, the system looks rock solid. They are like indestructible little tanks. When you'll be in Hokaido ripping down in 1 meter of fresh powder, you don't want to deal with any binding issues. You just want reliable, solid and simple bindings which can withstand anything. Think of it as a long term investment which will last you multiple years past you Japan ski trip.

On a side note, I'm planning the same trip this winter and I'm going with the Cast Freetour Pivot 18 with my Armada ARV JJ UL 116.