In fact, Trickster should also show files that are being opened in Preview and in Finder.
Also, Trickster uses not only Spotlight but also FSEvents. Saved and modified files are being tracked with FSEvents. It's also good since it allows tracking these changes in places where Spotlight might not index your files (such as inside ~/Library folder).
For example, you could use it to track new images coming through Photo Stream into your Mac.
I had the file opened in the app Preview and Trickster didn't know I had it open. But I opened another PDF in Preview and put in some markings on the text, using the highlighter and the line through text and Trickster did then see that file.
Well that cleared that little difficulty up then....
How useful is Trickster
I tried out Blast and found that it annoyed me more than I used it. I was planning to give Trickster just a try, seeing as there is a trial version. After using it for a while and liking what I saw I went ahead to get it from the Mac App Store. I can see it will be useful because when I use Alfred to try and find stuff, I have found it is not so good at finding the files I have been working on. Hopefully Trickster will do a better job.
It is pretty handy that you only have to open up a file for it to show up in Trickster. Mind you it didn't work with a PDF that I opened in Preview. I will have to test some more to see if it was only that specific pdf or if the problem is wider.
I like the Hot key to toggle the window for it on and off. I like that I can drag a file to another folder using Trickster too. I am starting to think that if I persevere with it I will wan to use it all the time. I went into the preferences and told it to ignore a couple of file extensions. Saves it getting clogged up and stopping me from easily finding the files that I want.
Remarkbox