If you put out very similar content with very little variation, e.g. it's always a beauty tutorial, then it would probably make sense to feature one of your higher performing videos instead of having a channel trailer. On the other hand, if no single video gets your full breadth across, then it's not going to be as useful.
Length plays a part too. General wisdom seems to be that a channel trailer should be short and to the point, with a clear call to action. If your videos are on the longer side, then that's something to think about. Is someone going to get hooked in that instance?
Finally, speaking anecdotally, I can say that my own YouTube habits tend towards preferring a channel trailer. I typically skip straight to the video pages if there's just a normal video there - there might be better content - but it's possibly a missed opportunity to hook me. My own stats tell me that my channel trailer has performed well and a significant portion of my subscribers seem to have come from there.
I don't know that there's a one size fits all answer here, but I think that there might be a once size fits most answer.