DON MORRIS  I was looking for the "Disk Hogs" feature, so I'll only comment on that. On my 250MB disk, about 75% full, the scan took much more time than any of the other utilities I tried. Also, considering only that feature, OmniDiskSweeper is $26 less (free). Add AppZapper ($13), AppDelete ($5) or AppTrap (free), along with any number of duplicate file utilities, and you can pay half as much (or nothing) for the same features as Sponge.  
(Version 1.2.1)

ESPIRIDION  It is interesting indeed, but performs like an early beta and it's not at the same level as alternative programs.

For example, to uninstall applications I prefer TinkerTool System.

For finding duplicate files, I prefer Araxis Find Duplicate Files and FileBuddy.

Both TinkerTool System and File Buddy offer dozens of powerful, well-implemented features.

I'm not mentioning the Disk Hogs option since it crashed on me, but I also have programs that have that specific feature.

I will not rate the software, but in its current state it is not something I would use.  
(Version 1.0)

CHRISWAN  A very interesting concept

combining 3 common utility into one

nice!  
(Version 1.0)

DAN CHAN  You won't believe how much long forgotten junk I found on my hard drive using the sweep disk hogs feature. Highly recommended.  
(Version 1.0)