I started buying this type of running shoe, back when they had the 1221... I loved that shoe, and then they stopped making them, and I had to buy the 1222, and then the 1223, and now the 1224... but I'm kinda over it.  I run an average of about 20-35 miles a week.  My 1224s (both pairs) just fell apart way too quickly.  I ended up switching out to another brand called Ghost... and I like them more that the 1224s, and slightly less than the 1221s.  I have to say that these shoes are just not worth the money.  I felt justified in spending that much money, when I was buying the 1221s, but these shoes are just not worth it.