If you do an update install, you probably won't run into any issues. If you do a clean install, you also probably won't run into any issues, but there's a small chance Windows 10 won't find a driver for one or more of your devices. Even if that happens, installing drivers is a piece of cake. If there's nothing else important on the computer (programs, files, etc.), do a clean install. If you have programs/files you don't want to worry about restoring, do an update install.
Off topic, but do you already know how you will be activating Windows 10 after the update?