Regardless of your favorite sub-genre of electronic dance music, a set by a DJ should take you on a journey. Now granted, that may be a little difficult if the set is short (20-60 minutes). In that case, the DJ must have the skills necessary to take your mind off of anything else in such a short period. Which is probably why those of us who have followed the evolution of dance music over the years respect those that gravitate towards longer if not open to close sets.
Perhaps the short sets can be attributed towards short attention spans from the crowd or owners, promoters, and/or managers trying strategies to get the crowd to buy more alcohol. This is also brings up the difference between festival sets and club sets. Unless a DJ/Producer wants to make a statement (requests) or somebody on the line-up does not show up, sets are usually an hour long during festivals.
The trance scene seems to be grasping on to the importance of a journey during a set more than any other sub-genre. Well known DJs/Producers have been requesting what is known as an open to close set more often. Now it can vary from 6 hours to 12 hours or even longer in length. Despite attempts by many, Markus Schulz is known for his marathon sets! It only makes sense when he has spoken about starting as a resident DJ in Arizona where he was used to opening and closing the infamous club The Works. If you have not had the change to experience one of these sets, it is strongly recommended. The journey you embark on is really hard to describe unless you experience it. The art form is better for it.