There's always a lot of debate about the value of weather sealing. First of all, weather-resistance is not absolute. In fact, Fujifilm doesn't provide any information as to the quality or WR or the tests that cameras and lenses need to pass. That means that we have no clue to what extend the WR-badge 'protects'. To my knowledge only Leica provides you with an IP-rating which indicates what standardized tests the camera and/or lens is able to pass. Fuji's -10 C claim is a quite generic one. The past 35 years I haven't had cameras unable to operate at -10 C. Regardless of brand or the WR-status.
The weakest point of an ILC is obviously the lens mount. You should avoid changing lenses under challenging conditions unless you can provide protection against direct impact. That means that lenses with rubber gaskets also protect the weakest point of a non-WR camera.
In my experience (I meet a lot of enthusiasts in workshops) most amateurs are quite meticulous about their camera and lenses. Just some generic TLC will go a long way, also for non-WR cameras. Submerging your camera or leaving it unprotected in a downpour or snowstorm, can lead to immediate failure. If not, then you were lucky. WR only protects a little against that but not entirely (not at all to submerging by the way).
The real issue is the long-term threat. Dust and moisture gradually builds-up inside the camera and starts corroding the contacts and print boards, resulting in strange and erratic failures until complete shutdown. WR helps a little bit in this area. But when your camera survives the rain, it doesn't mean that you're in the clear. Always wipe dry your camera. Esp. around the dials and buttons. Also when your camera is WR. If the elements are really severe (monsoon season or arctic winters) I would always use a rain cover. Regardless of WR or not.
Sometimes people claim that WR doesn't make a difference at all and that most cameras in repair are actually WR. That's a bit misleading imo. Cameras in repair are usually the more expensive cameras, where repair is worthwhile. These more expensive cameras are mostly WR, so that messes-up the statistics. Next to that, these are also the cameras mostly used under severe conditions, so eligible to more potential damage. Esp. when their owners have complete faith in the WR-badge.
So, in short, if you like the X-S10 and you apply a little TLC it shouldn't be a problem. Just avoid the severest of conditions and if not possible, use one of these cheap plastic rain covers.
