I need to replace my 2012 Retina MBP 15". I thought about going 2018MBP, but my needs have changed and don't need a heavy duty mobile rig anymore as I'm doing much more work on my iMac at home. So I thought about getting one of the Integrated GFX versions from 2013~2015. The price/performance differences are making me lean towards getting something older, but I wonder if there are any significant issues I should be aware of - and if I should just aim to get the 2015 integrated model.