I bought GR5 15 days ago. Prior to this i used GR3--probably my fav shoe ever. I love the GR5 so far. Fit was a lil tighter than GR3. My biggest issue is that every time i played with GR5, i developed Knee pain. It happened enough times that it isnt a coincidence. I am considering ordering a higher size (would they exchange--i ordered it from TW) OR may be try changing INSOLES and see if that helps. May be it goes away after some breaking. Anyone had similar experience with ASICS or any other shoes?