Differences about calibration software? (Spyder4Elite vs DisplayCAL)

Question

I have a Spyder4Elite with Datacolors software running in Windows. I also use that Spyder4 in Linux with DisplayCAL, and have some questions about those two calibration softwares:

1. Datacolors software is just plug and play: I plug it in, press next a couple of times and it's done. DisplayCAL needs me to adjust the monitor first (brightness, contrast, and RGB-gain), before calibration begins. Does Datacolor adjust the monitor for me by programming the graphics card? And is it just that DisplayCAL does not have that functionalty? Or is it something else?

2. Another "major" difference is time: Datacolors software used well inder one hour to calibrate the display, while DisplayCAL spent several hours. Why? Is Datacolor just better, or is DisplayCAL more thorough/have higher quality?

3. After calibration, the software writes an ICC file. Can I use that file on any computer, any OS, as long as it "follows" the monitor attached?

4. My monitor (older Eizo SX2762W) has a 16-bit LUT table. Does it matter to me or the calibration software?

Answer 1

1. DisplayCal suggests calibration only if you select anything other than "As measured" on calibration tab. You may skip the calibration even if it is suggested, it won't result in less accurate profile. You may also set "Gamma" (video LUT) to "As measured" because it does not affect colorimetric application.
2. If you see patches changing at same speed, you have just selected too huge patch set under "Profiling" tab and that results in better profile. If patches change much slower under DisplayCal, it is the issue of the software.
3. Yes, as long as video card settings are always neutral.
4. Yes it does but I cannot tell how exactly.