the only I could see was the rokinon 12mm f2.0 $300.
That's a very good lens for that price, if you don't mind manual focus. And for wide angle lens and shooting stuff like landscapes, manual focus should not be a problem. Especially on a mirrorless camera that offers great manual focus aids, like magnification and focus peaking. It can only be problematic in really bright sunlight, when it gets hard to clearly see the display. But for "infinity focus", you can just mark the optimal focus point on the barrel and focus that way, without even looking at the screen. This should solve any focusing problems for landscape work.
As for my personal opinion. I think Micro 4/3 offers a greater room for growth for the future and there's quite a bit of variety in this ecosystem. With both new lenses and bodies coming out every year, it's getting better and better, and there's less and less of stuff it cannot do. But then again, I'm biased, as I am an MFT user myself. So I already made my choice. And I would make it again.
As for Samsung, there are those rumours that they will exit the camera business. I don't know if this matters to you. But if it's true, it may mean that there will be a lot of very cheap Samsung cameras and lenses (both new and used). So that option might simply become irresistible because of the price. But for me, Samsung was a curiosity at best. I never treated their camera efforts seriously, as they never treated their users in my country seriously (in that they never sold the good stuff here). So you can even say I'm biased against Samsung. So keep that in mind when reading this.