K&N replacment air filter

I'm just wondering if anyone has ever tried one of the performance replacment air filters like the K&N? I need to change ours before a long trip this weekend and I'm just wondering if the price difference is worth it or not. A normal filter is about $15, the K&N with all its performance claims and 10 year warranty is $40. It is direct replacment and drops right into the existing filter box. Has anyone had any experience with these?
Thanks

I think most people are kind of split about K&N. Some love them because they flow more, but some hate them because they dont actually filter very well due to the high flow. I think of it this way: Would I rather save $100 on filters, or risk spending thousands on a new engine or car?

I totally agree. I'm not interested in the short term performance gains if they come at a long term cost of lost engine longevity. But I don't mind paying the extra if the filtration is really there too. That's mainly why I was wondering if anyone had any direct experience I could pull from. Thanks for the reply.

My experience is that they actually filter better. They aren't the free ticket that they appear to be though. You have to clean them with special cleaner and I believe you should apply a special oil to them so that they will attract small particles better. By the time you buy cleaner and oil, you spend nearly as much as a new filter.