I think the G30S is better except that the grip sucks. I got my frame cut and it is amazing now, but if you don't want to do that and the grip doesn't work for you then go with the XD. If you can find a LGS that has one so you can feel it in your hands first is a good idea. G30S are a bit rare, the frame is an SF frame, only in Gen3. So a Glock 30SF has the exact same frame and are very common, you can sample that frame and keep in mind the slide on a 30S is thinner and that is comparable to the slide of the XD. The durability of a Glock is greatly superior to Springfield, keep that in mind.
A LGS will likely have a Glock 36 and a 30SF and no 30S. If they do, maybe they can swap the slides on them so you can sample what the 30S is, 36 slide on a 30SF frame. In fact, you can purchase both and have a modular option. 36 when you really need something smaller, the 30S will likely be your favorite, but the 30SF will be the easiest to shoot with heavy ammo or even 45super as a woods gun. You can even get a 460rowland conversion for the 30SF slide, slap your 36 slide back on when exiting the woods. The 36 is an excellent backup. The Gen4(Ambi) frame can also be used to put your 36 slide on, but the 30S is only sold with the Gen3 frame, sadly.
I have a feeling the Gen 5 30 will be a thin slide version only and it will probably be compatible to swap slides with the G41 and G21. That would be cool.