I want to buy a nexus 4 but...

I want to buy a nexus 4 but i am kind of worried since I have read in many threads and in the Verge review of the new nexus 7, that the 2012 nexus 7 hasnt aged particurally well. Since I usually keep my phones for 2 years I dont want my phone to become slow and unusable. I currently use WP (which I love) but I like to change. should I really be worried? Have you noticed your nexus 4 drop in quality?

Sorry for my english, I am Greek.