Personal experience with processing is a subjective thing (unless it is accompanied by some empirical data), and so there is no reason to think that there is anything wrong with your reels. The fact though is that Expert drums offer the most even and smooth processing, with the least handling of films. That, coupled with a high per run capacity and low min chemistry requirements, are some advantages the Expert system has (at least in 4X5).

And so - the fact that Expert drums are considered (and decidedly proved) to be superior does not necessarily indicate a problem with the 2509n reels (which are fine and offer their own set of advantages on their own), only that you can get even better results from an Expert drum.