As I mentioned in another one of my threads, I currently use Shadow Defender, which is small and has a nice clean simple UI with nearly everything I want in a freezing/shadow type of app, except for shadowing to RAM. Below are my comments for RVS Pro: PROS 1. Browse registry feature is useful, although this is extremely basic. For example, Can't copy keys Can't select/copy multiple values in one go Can't delete a value/key CONS 1. Not a fan of the skinned UI. <RANT> Why oh why do individual vendors feel the need to add their own skinning to each app, thereby bloating it up and making it look ugly ? Windows has it's own theming system, and if I really wanted to skin further, then I might use something like Window Blinds, so I can get every app looking the way I like. Use standard windows controls, and let the users customise the look. Less, is more, as they say.</RANT> 2. UI layout isn't too bad, but still nowhere as simple as SD's. 3. No display of space used by virtual mode 4. No option to drop or keep changes on confirmation dialog when stopping virtual mode. The Virtual Mode settings should be used as defaults for the options on this dialog, thereby minimising clicks. 5. No context menu entry for files/folders to commit changes (with options to also commit deletions or deletions only) If I set the "Percentage of free disk space used for the Virtual Mode" to zero percent, does this mean it will only use RAM for the cache ? Suffice to say, I'll be sticking to SD (if only it had RAM caching), although I'll be keeping an eye on RVS.