Only caveat about downgrading to Windows 7: Some machines (mainly low end ones) can come from the factory only allowing what is called UEFI Secure Boot. This means it boots Windows 8 or nothing. Trying to boot Windows 7 just won't work, period.
Of course, there is the option of using virtual machine software. I have some accounting software which requires a backlevel Windows version, so I have that in a VM, while everything else just runs on the latest Windows.
In Windows 8 Pro, you get Hyper-V, one virtual machine tool. There is also Virtualbox, and if you don't mind paying for the upper-end features, VMWare Workstation.
If you don't mind the tiles interface, that is always an option with Win8.