What will you use it for?
Are funds limited?
Do you need a lot of storage?
The 16GB RAM is IMO a bigger upgrade than either, in many cases.
The jump from 512GB to 1,000 GB isn't a very good value...you are paying almost a dollar per GB!!! Is using an external hard drive or a NAS setup practical for your needs? If so, how fast a speeds will you need?
Funds are indeed limited. I have enough for either configuration. The 16GB of RAM is in both options, so that's is a must have. I will be using an external HDD or SSD for backups and whatnot...and I'm not a professional videographer, so speed is not of the utmost importance...it is however, nice.
Storage but unless you know you'll need that 1tb SSD then neither save some cash.
... it's not about performance at all. It's about on-chip TB3 support.Not a big difference in the Kaby Lake CPU that is likely to be in any 2017 MBP.
Would buying a 2015 15" be a bad move in 2017? Seeing as how they have a fourth generation Intel CPU?