TechOxi

Windows 10 has already passed 68 million installs by the 2nd day of its actual release. This is a pretty strong indication that Windows 10 is more better than Windows 8/8.1.
I strongly recommend you to install Windows 10 by using USB and i think this is how Windows will retail as Microsoft is now ditching DVD discs.

Download Rufus
Run it with Administrator rights.

Step 1. Select USB
Step 2. Select “ Select MBR partition scheme for BIOS or UEFI “
Step 3. Select NTFS for File system.

Make sure you select these three options are checked under Format options.
4. Quick Format
5. Create a Bootable disk using ISO Image
6. Create extended labels and icon files

Step 7. Select the Drive icon next to ISO Image and then select ISO file
Step 8. Click Start Button
That's it..