I enjoyed my Conti Motion as well, but I will say that it doesn't last as long as it could. Both the one on my bike, and the one I mounted on a friends bike were toast around 7k miles (rear tire -- fronts seem to last much longer, I'm at ~10k on the front with lots of life left). It's still good value/mile, but not quite as much as you might think. If you pay to have your tires swapped the savings are probably non-existent.
Conti - $79.08 / 7k miles = $.0113/mi
PR4 - $166.87 / 11k miles = $.0152/mi (+$.0039)
Figure the Average Joe riding 10k/year that's about $39 saved per year. Prices from American Moto Tire today, for reference. YMMV, of course .