Nike Nucleus Retired with 247 miles

I ran 4 miles today, 9:10 out and 7:57 back. I wore my new Nike Nucleus shoes and they felt so good I am retiring the old Nucleus with 247 mi on them. I had no twinges of right Achilles tendinitis present since about 175 mi on the old Nucleus. I think two factors led to the old shoes breaking down. First I was not tying them snugly enough so my feet moved around in the shoe. Second, I was landing on my heel not flat footed like now.