Disk Defrag is a massively popular piece of freeware, and with good reason. It runs faster and provides more information both during the defrag process and afterwards than the native Windows defragger, and it's free. Effective and providing an essential function, there's no question that your computer runs better for it.
BoostSpeed, while effective, isn't necessarily what every user needs. It bundles Disk Defrag with all the other Auslogics utilities. These include a Registry cleaner, an uninstall manager, a startup manager for boot cycle customizations, RAM and browser optimizers, file shredder, DirectX diagnostic, Windows tweak manager, and several mini apps to manage Windows settings. It also comes with a rescue center that can back up any settings before you change them. No doubt, BoostSpeed gives you your money's worth, at least in terms of services provided. Upgrading also only costs $10, for those who own older versions.
Are they all worth paying for? That depends on what kind of user you are. Most if not all of these features are available as freeware from one vendor or another, and generally one in each category is top-notch or nearly so. Some of the lesser tools, like the tweaks manager and the security feature, didn't live up to my expectations. Tweaks focused on basic functions and wouldn't serve as a replacement for TweakUI, while the security feature merely let me know that I had up-to-date security apps installed. Still, the convenience of having all these tools located under one umbrella is hard to argue with, and even the tools that didn't impress did their jobs free of hitches.
Scan speeds for the other features included here are comparable with those in Disk Defrag. Users also get the convenience of optionally setting the program to run at startup and live in the system tray, making most of the program's functionality no more than a context-menu click away.
The most useful tools are the Disk Defrag, the RAM optimizer, the Registry Optimizer--if you believe that "optimizing" the Registry is more than snake oil--the file shredder, and the performance monitor. The 15-day trial comes unfettered, allowing you to thoroughly judge if BoostSpeed is a program you need.