I like that Diptrace supports hierarchy, and I use it a fair bit. One thing I can't stand is the way diptrace names parts from the hierarchical schematic, with a series of numbers interspersed with underscores representing the index of repetition form each level of hierarchy. Well, I didn't say that well, but I think you know what I mean.
The naming convention makes sense and has some advantages (like when you are doing a matrix of something and you can tell what row and column you are in), but it results in ridiculous refdes like LED_3_2_2. I'd much prefer just simple numbering, or the ability to "flatten" to simple numbering toward the end of the layout process.