Mine is an Early 2014 Model in Pristine condition (I use it even today though with Win10 running in Bootcamp).
(Still under 1 year of remaining EXTENDED warranty till November 2017 )
The config is as follows:
Model: MacBook Air 13 inch (Early 2014 model) and using it since
OS: MacOS Sierra (version 10.12) the latest and up to date (a week back),
Processor: 1.7 Ghz, Intel Core i7,
Memory: 8GB DDR3 (1600 Mhz),
Graphics: Intel HD Graphics 5000 1536 MB,
SSD: 512GB+128GB (Transcend JetDrive in the card slot) Please google for more info.