Worth getting 2015 Macbook Pro instead of 2013 Macbook Pro for eGPU setup?
I really prefer the form factor of the 2013-2015 MBP to the later ones.
I am contemplating getting the 15" 2015 without dGPU instead of 2013 with dGPU for eGPU-centric setup.
I read that 2015 has 4x PCIe I wonder if that would make the upgrade worthwile?
Also I am tired of dealing with Bootcamp etc shenanigans because of the 750GTM in the MBP2013
While the 2014-15 models are awesome, I do think that the 2019 16-inch model makes a convincing case. In your position, I would just wait it out until a 2020 model with WiFi 6 comes out. I just see little value in moving from a 2013 to 2015 model overall - unless you are absolutely dead set on getting a 5-year old system to replace your 6/7-year old model. That being said, value is subjective anyway. Do what you feel is best. Community support is here either way.
The only PCIe difference between the 2015 MBP vs. the 2013/14 models is that the 2015 model has PCIe 3.0 x4 lanes for SSD, while the older ones have PCIe 2.0 x4. The limitation is Apple's SSD, which was restricted to 2 PCIe lanes if I recall correctly. All of this has nothing to do with eGPU unless you plan to run it like this: https://egpu.io/forums/bootcamp/mid-2015-15-inch-macbook-pro-egpu-master-thread/