I had the wave inspire 6 and I loved those!  I never had any problems.  I purchased these about 2 weeks ago and I love them too.  I enjoyed the inspire 6 better -- because I never had to "break them in."  The inspire 7s seem to need to be "broken in."  I have  had to buy the wides because I have a wide foot and them inspire 7s seem to be REALLY wide, they don't really hug my foot as well as the 6s.

Overall though, I like mizuno's and I will continue to buy them.