WinDirStat

Quick, bullet-points review.

Winner: Space Sniffer.

Goals

• Informative visualization of space used by directories and files
• Full file delete support
• Good User Interface
• Fast Scanning

Visualization Types

• Hierarchical Cake Diagram
• Cake Diagram
• (Hierarchical) Treemap
• Absolute Bar Chart
• Relative Bar Chart

WinDirStat (3/5)
+++ Both relative bar charts and a treemap

• File type based statistics

• Sometimes unresponsive while scanning
• Quite ugly
• Visualization sometimes very slow
  -- Does not monitor disk for changes
  -- I find it hard to use the treemap for anything but finding single, large files
  -- Sometimes reports wrong sizes (happened to me in Divx player cache directory, anybody got an explanation?)
  -- Can only delete single files / directories
  --- Slow! (~ 4 minutes for my C drive)

Mind Gems Folder Size (2/5)
++ Useful, good-looking and informative non-hierarchical cake chart + relative/absolute bar charts

• Ads in toolbar (for developers software)
• Delete function disabled while scanning, should be possible if current directory is completely scanned
  -- Does not monitor changes on disk
  -- No hierarchical visualization (treemap / hierarchical cake) at all.
  -- Sometimes deleted items do not disappear properly (only after F5)
  --- Slow! (~ 5 minutes for my C drive)

SpaceSniffer (4/5)
+++ Treemap-Visualization with adjustable detail, navigation, labels (what WinDirStat wanted to do)
+++ FAST Scanning
++ Gives you full explorer context menu

• Powerful filtering (not very comfortable to use)
• Tagging
• Active Development
  ~ Donation Button, non-obstrusive
  ~ No installation

• URL in Window Title (ugly!)
  -- No simple bar chart visualization possible.
  -- Can only delete single files / directories
  -- No "open explorer here" if not included in explorer context menu
  Tip: Disable distracting Mouse Trail
  Tip: Disable Console Popup
  Tip: Enable File Type highlighting

TreeSize (4/5)
++ Simple!
++ Quite fast scanning

• Simple filtering
• Can also display File Count etc.
• Explorer Bar Chart visualization well executed
  ~ Software Ads, non-obstrusive

• Can only delete single files / directories
  -- No other visualization options

SpaceMonger (2/5)
++ Favorites
++ Statistics

• Multiple File selection
• Fast!

• Ugly
  -- Awkward
  --- 30 Day trail :(

jDiskReport - No delete function => no rating
++ Savable scans
++ Statistics (Type, Size, Date)

• Also visualizes file count per folder

• Java Interface (ugly!)
  -- Slow!
  --- No delete function at all

OverDisk - No delete function => no rating
+++ Beautiful, exact display of folder size structures using hierarchical
-- Does not monitor hard disc
-- Hard to get a quick overview since diagram does not contain labels (only mouse-over)
--- No delete function built-in

Best Speed: Space Sniffer
Best Non-Hierarchical Visualization: Folder Size
Best Hierarchical Visualization: Space Sniffer
Best User Interface: Space Sniffer
Best Delete Behavior: Space Monger

Others:
Folder Size (by Brio) - Only works for 2000 & XP
Sequoia View - Original Treemap implementation, very basic
Xinorbis - Failed to start
Disk Space Fan - Huge interface delays

Also many advanced filemanagers support basic display of folder sizes or even visualization, like FAR, FreeCommander, TotalCommander.

After all these years without an update, it's STILL the best of them all.

Runs quick (faster than JDiskReport) and stable on Vista business 64 bit.
I think it is the best application compared with the alternatives, and it allows to examine network drives for free.
TreeSize Free can only examine local drives.

nice app to find what to delete when you are running out of space.

It shows a good visualization of all folders and files.