Yes week for week this year is a lot less busy in the clubs than last. Last year people were complaining about lack of tourists which may have been true, but they all went to the clubs which were jammed full.
This year there seem to be a lot less "tourist clubbers" (the one that just come to see what all the fuss is about then leave at 3pm because they are tired.
The pure Pacha night on the Fri was much busier than the Def mix or Subliminal (Wed) nights and was still quite full when it shut at 8.30am! But in general the clubs have been just right. Not too full that you can't move which made most of them a nightmare untill 5am (when people started to leave) last year.
Cream was just about right this year compared to a shoulder squeezing nightmare last year.
Manumission took a few hours to get going and could have done with a few more people (again still better than being too busy as it has been for the last few years) but was really good to have dancing space and be able to get to the other side in less than an hour
Base bar and Ibiza town were fairly quiet too
Pinup was packed (but not to the point of discomfort)
In many way's it still busier than it was in the mid 90's and I preffer the numbers as they were by a long way. Sitting outside Cafe Del Mar with the other 30 people was a lot better than sharing it with 100's and countless other soundsystems!
Expect the numbers to grow as the season goes on though as now is early for most people.