I've been using defraggler for a short while and it's pretty good. I only have few comments about 1.02.077
Make the fact it is beta a lot more obvious. I spotted the new version last night, downloaded and started running it at home. Only this morning did I twig it was beta. Please put the warning at the top and provide a link to the previous stable release on the download page.
It's very, very slow. On a drive which had previously been de-fraggled, it seems to be moving every single file about and creating masses of fragments. This is my home PC and it has been running for a good 12 hours now (300gb drive, 200gb data). The PC seems to be stable, so I am not overly concerned about data loss, I am just wondering what on earth it is doing!
New UI. Sorry, I don't like it. Too many clicks. I selected the files and then stared dumbly at the screen whilst I looked for the defrag button. Obviously I found it, but I think it is now doing way more than I asked it (I only wanted the selected files defragged, not got a clue what it is up to).
Automation. I noticed "df.exe" this morning as well. I am going to guess that this is a command line so I can knock up a quick batch file and have that run at some specific time, would it be possible for defraggle to offer the ability to schedule such a task via the UI? Might help total beginners.
Monitor. I realise this may be bloat, but what about adding a feature to monitor driver(s)? A system tray icon which would pop up a message if the scheduled analysis (e.g. nightly) indicates that defragging might be a good idea. For this and the last one, defraggle should have the option wake the PC from any sleep-state it may be in to ensure the job gets done.
All in all, a good product, although I think I will stick to the previous release for now.