I guess its a bit of both.

Had it been about 5 years ago, I would spend days trying to figure out how to incorporate a software with a cool feature into my workflow. Now though, and I'm not all that old, I don't have time at work to spend trying new things, unless it will vastly improve my efficiency. So far based on what I've read about QS specifically, it doesn't provide me anything that my current speed on a keyboard/mouse/trackpad + expose + spotlight doesn't already give me.

With software in general, the 15 minute rule applies during the work day. I just don't have the spare time, with some exception. For example, my current "task" is to figure out if virtualization will help our server solutions at work. So for the next few weeks I"ll be experimenting with VM Ware and whatever else I can find.

At home, I've tried QS, I just don't have the time to spend figuring it out. I have a wife and kid I'd rather spend time with, and I have an HD tv + other assorted toys that rank higher on my priorities than the examples of how QS could speed my tasks.

There are a lot of cool features on the Mac that have saved me a ton of time. But, the truth is, and I'm sure most of the "many things" you have encountered on the Mac fall into this as well, you could figure out and were intuitive and required little or no learning curve. That's what drives people to the Mac, "it just works", and things are where you think they are going to be. QS, to me wasn't intuitive, and thus hasn't gotten much of my attention, and hasn't ranked higher than playing with the baby while podcasts (you are one of my favs on MBW by the way) play in the living room.