new shoe problems...ouch!!

Question
Hello,
I just purchased some of the new Asics Kensei running shoes (size 11). I went for my first run in them today and got a couple of incredible blisters on the inside of my heel. Why has this occurred and how can I make sure it doesn't happen again? Have I purchased a size too small? The wrong shoe for my foot (on the water to paper bag test, I registered as having a "normal" foot strike)? I would really appreciate a reply on this as the window to return the shoes is ever closer everyday. My previous shoes were Nike Shox. I had no blisters with them even the first time out. They were size 11.5, but I just figured that shoe sizes may vary between companies. Am I wrong? Please help. I really would like to make these Asics Kenseis work!
Thank you for your time,
Evan

Answer
Evan,

Everyone has different experiences with shoes. Blisters may be because they are new and need to be broken in, and they may not be. From my experience though it is best to stick with one brand. I had Nike and switched to Asics and had problems also. I know a few people who could where one or the other but not both brands. I would stick with Nike if that is what you've been wearing.