I got the UX305CA (1920x1080 version, 8GB RAM) and I love it! Small, light, completely silent, and the screen colors are great out of the box! I calibrated both my once-top-of-the-line home laptop (Clevo W870CU from 2009, i7, 8GB RAM) and this one side by side one evening, both to D65. The UX305CA’s screen covers 98% of the sRGB gamut, is capable of a very high luminance (I capped it at 120cd/m2 but it could do more), does not change much after calibration and profiling (meaning it looks great and the colors are close to what they should be even if you don’t have a colorimeter), and the colors look good from a wide range of angles. In comparison, my home laptop’s screen covers about 70% sRGB, fails to reach 120cd/m2 after calibration and profiling (reaches just 80cd/m3 - if I reset the video card gamma table to linear it gets significantly brighter but that’s because it gets significantly bluer), changes very much after calibration and profiling, and the colors change dramatically with a small change in viewing angle.
Haven’t processed raw photos with it yet. Your question is not really a question of speed, it’s a question of RAM. This one has 8GB, so you can process raw photos and run Firefox and do whatever and it will be snappy as long as you don’t run out of RAM. Further, GIMP (2.9) is extremely slow and non-optimized regardless of hardware - getting it to run faster is a question of optimizing code, not of throwing more CPUs and matches and gasoline at it. I hope this gets addressed once the tremendous task of porting everything to GEGL/BABL is done.
My OS with KDE Plasma loads in seconds from a cold boot and feels very snappy. Can’t say the same for my i7 home laptop.
The touchpad works great, for a touchpad. It has no faults or jumps or anything like that. There is one thing I wasn’t expecting, and it’s a touchpad-shortcut that lets you scroll without having to move the cursor over to the scrollbar. Odd things can seem to happen before you discover and identify it. Once you get used to it, after an hour, it not only stops annoying you, but becomes handy. There might even be a way of controlling it through touchpad settings in your OS. Still, I don’t like touchpads in any shape or form and mostly use a mouse.