When comparing Process Hacker vs Ditto, the Slant community recommends Process Hacker for most people. In the question“What are the best power user tools for Windows?” Process Hacker is ranked 8th while Ditto is ranked 20th.
Specs
Ranked in these QuestionsQuestion Ranking
Pros

Pro See programs with active network connections

Pro Real-time information on disk access
Pro 10x more detail and information about usage of PC resources and processes
Pro Can be set as your default task manager

Pro Detailed overview of system activity with highlighting

Pro Can create, edit and control services

Pro Can track which processes are using a file

Pro Open source
You can find the code here.

Pro View detailed stack traces with kernel-mode
Supports WOW64 and .NET.

Pro Graphs and statistics to quickly track down resource hogs and runaway processes
Pro It's reliable, fast and quick
It just works...always. It's fast and quick, which can save you thousands of hours.
Pro Very configurable
You can set all sorts of things from size of database to size of individual clips, types of objects to copy/paste, which hotkeys to use etc.
Pro Scriptable clips
Clips can be used/changed with scripts during copy or paste.
Cons
Con It might be a little intimidating for some users
Con Uninstaller removes nothing
After uninstalling removal of almost every file manually from different directories is still necessary since the actual uninstaller only displays "other files still remain".
Con Minimizes after each paste
You have to activate it twice to paste twice.
Con Does not support HDPI displays
On high DPI/resolution displays, the UI is very small. Practically unusable.
Con RTF bug is still present in latest Beta version
You can turn on the option to draw RTF text in the clip list, but it no longer works in Windows 10 Ditto (64bit), and the latest Beta version available today - which claims to have fixed the bug - still has the same bug. It will no longer draw RTF text as-is in the clip list.
Con The UI is very confusing
Con Can't use any shortcut you wish
Anything with spacebar, windows key (that the system also uses) is not possible.
Con Portable version will remove all clipboard record once it is updated to newer version
