Snappy Driver Installer is a reliable driver updater that is free and has no limitations, no premium features, no adware, no gotcha. It's easy to use in the default mode and it has a lot of useful advanced features in the expert mode. It has the most advanced driver ranking algorithm that by default prioritizes most compatible drivers over recent drivers in order to minimize the risk of installing sub-optimal drivers.
As soon as it starts for the first time, it suggests downloading indexes and driverpacks(archives with drivers). You can download all driverpacks(over 12 GB) for offline use or download only indexes(10 MB) in order to see which driverpacks you actually need for your current PC. Downloading the whole package is recommended if you want to put it on your USB flash drive or external HDD and use it as a portable tool to install drivers on many PCs. If you want to install drivers only on your PC, you're better off downloading only indexes.
Snappy Driver Installer has an internal torrent client, so you'll be able to download drivers at the top speed. Each time you run Snappy Driver Installer, it checks for updates and you'll be notified when updated software or driverpacks become available and you'll be able to download them via the app itself.
PC technicians can enable the expert mode which provides detailed information about drivers in floating tooltips and allows you to choose installing alternative drivers instead of the recommended drivers. It also unlocks other advanced features. For example, it's possible to make a driver backup using the 'Extract to...' button; or remotely troubleshoot driver related problems by asking users to send you snapshots that are created by their copy of Snappy Driver Installer, so that could load it in your copy of Snappy Driver Installer and see what's wrong with their setup.
Overall, Snappy Installer is a great tool for computer technicians and home users who would otherwise would have to go hunting down drivers on manufacturer's websites.