Both DPS and SDI use the same driverpacks(made by SamLab). However, DPS doesn't have the full set of driverpacks because DPS cannot install some drivers without rendering system the unbootable(notably, Intel USB 3.0 drivers aren't included in DPS). On the other hand, SDI doesn't have these problems, so it has the full set of driverpacks.
Keep in mind that driver updaters have to work with incomplete/incorrect information and have no means of testing all drivers on all available hardware, so some difficult decisions have to be made and driver ranking algorithms needs to be fine tuned from time to time. Most driver updater try to suggest installing as many drivers as possible because it's considered to be advantageous from the marketing standpoint and they want to have the bragging rights of always picking the latest drivers. Also they may pretend that the driver installed successfully when it actually failed and cover up the failure by rolling back to previous driver and never suggesting installing that driver again(HardwareID can saved in the registry to remember it between sessions). Their main goal is to get as many users and force adware on them. This 's why they try convince users that they absolutely have to keep their drivers updates all the time or they're gonna have a bad time.
SDI was designed for technicians to solve actual problems such as installing missing drivers after installing Windows or fixing driver related problems. SDI by default won't suggest updating working drivers unless it's confident that the new driver is better than the installed one in order to minimize the risk of ruining the system. The user still has an option to install newer drivers by changing filters or opening the drop down menu.
The development of DriverPack Solution had been abandoned for years. If you compare the source code of DPS 15.10 and DPS 11, you'll find out that no one was working on improving it all these years. Only driverpacks and bundled software were being updated. Over time DPS accumulated many issues that its users have to deal with on regular basis such as avoiding installing touchpad drivers on desktops, installing several drivers on the same device(especially audio drivers), etc.