If you can swing the base 2015, I wouldn't hesitate. It's a solid machine and should easily last you years. It also has the latest features, and in terms of resale down the road it'll hold value better for at least a year.
Also worth noting - I went with more memory on mine (512), thinking I'd need it for sure. After loading up all my music, files, apps, and games, even on the 256 I'd still have a solid 100GB open. In the long term I'll probably use more, but overall it's probably more than I need. As I needed the dGPU it was part of the deal, but even so, it's worth figuring out your actual needs for what's stored on the MacBook Pro. For me it was less than anticipated without giving anything up.
But being perfectly honest - the amount of power you get for the trade off is totally worth it. You can get a nice USB drive that's 1-2 TB and small enough to slip in a bag for well under $100. But we're talking about a 6500 Geekbench score on the 13" vs a 13000 score on the 15". That kind of power will last you years, and that big screen is glorious.
RAM is something to consider as well. 8GB in the 13" isn't bad, but it's all you'll get on the machine. The 16GB on the 15" is overkill for most things, but paired with that beast of a processor it will give you a lot more longevity and ensures you've got RAM for future needs.