Well I took the plunge anyway despite the lack of a demo version of Scrambler. I encrypted a folder with a size of 96MB containing 14 mp3 files using a four digit password. Scambler took about 15 secs to encrypt. I decrypted the file again into the folder it was, and then noticed that Scrambler takes 907MB of memory after completing its task. I don't know if that amount is problematic as my MBP contains 8GB RAM, but it strikes me as quite a lot.
Nonetheless Scrambler is a pretty cool and very useful app, simply drag files or folders to the menubar icon and enter a password. I would prefer for future versions a preference menu option and the possibility to drag files and folders to a Dock icon instead of the menubar icon (it's cluttered with icons already).
The 250MB limit is very annoying however, please release that limit asap.