If you wanna fast, prompt and have every single update, than You buy Nexus.
I wanna have Sony and dont mind about updates. Xperia Z is still very powerfull device and it will have developers and we shall have many Android L roms.
Sent from my Sony Xperia Z C6603 using Tapatalk
GSM: SONY Xperia Z C6603 - Black --- SAMSUNG Galaxy S3 GT-I9300 - Pebble Blue
ROM: Android KitKat v4.4.2 / build 10.5.A.0.233 Denmark "3" / stock kernel --- Android Jelly Bean v4.3 / ArchiDroid v1.7.18 / Boeffla kernel v5.4 beta 2
LCD: 5" Sharp 1920x1080 TFT LCD / Dragontrail --- 4,8" 1280x720 Super AMOLED / Corning Gorilla Glass II
MSD: SAMSUNG Pro 16GB MicroSDHC Class 10 FAT32 --- KINGSTON 8GB MicroSDHC Class 10 FAT32