Hey Olimoronio, I got the Creative HQ1600 on Friday and I had a chance to listen to them for a few hours. Man - your description was right on! The extension and detail are great, the bass is super tight and fast (just the way I like it)! I love how I can hear the vocalist breath-in before singing on some of the tracks.
IMHO the sound is just amazing - regardless of the price. I was at BestBuy today (to spend my free reward zone gift card) and I listened briefly to the Beats Pro. I cannot believe they are able to charge $400 for them! The low end is so flabby and bloated - there is bass all the time regardless on whether it's on the recording or not. In comparison the HQ1600 are much more accurate, natural but still fun.
On the other hand, I wish the construction on the Creatives was a bit better. Mostly plastic... We'll see how they do in the long run. However; their construction makes them very light and fairly comfortable.
They pair very well with the iPhone 4 - nice crisp high end and nice range. The sound out of my clip+ was warmer but not in a great way. I still need to test them out with my other sources.
But in short - so far I am blown away! I hope they don't become another FOTM set, but who knows...