The 2015 MBP is a work horse but it too had issues with external monitors. I used to connect it to two external 1080p monitors one via HDMI the other with some ancient adapter. When I plugged in the latter my internet would suddenly stop working. This was apparently from a multi year bug where the ports adapter was so close to the wireless card that it interfered with the wireless cards normal operation. Upgrading the adapter fixed the problem (it was one of the old display adapters with physical pins you had to screw in) - took a very long time to debug that issue!

Does it have two GPUs it switches between? One high perf and one integrated?

When I had a MBP 2015 I rarely had the fan come because it only had and and used an integrated GPU.

With a 2018 MBP the fan frequently kicks on because it switches to the Radeon high perf GPU when doing things like connecting to an external monitor.

It's technically consistent, Windows just chooses to rasterize non-DPI-aware applications at the lowest common denominator DPI and scale them up on high-DPI monitors. AFAIK MacOS does the opposite, and rasterizes everything at the highest DPI and then scales down as necessary. The latter looks much better so I'm not totally sure why Windows doesn't do it - perhaps a compatibility hack for apps that expect classic 96dpi.

Newer versions of Win10 actually have an odd variant of this that works more like MacOS where it will sometimes rasterize at a higher DPI and scale down - it looks pretty nice but it's not compatible with all old applications, I only have it enabled for a couple.

But those apps were written for specific resolution and you (probably) cannot make them render themselves with higher resolution. And MacOS unlike Windows simply doesn't support running old apps.

I've never had an NVIDIA driver with it on by default. I've run two different computers with NVIDIA GPU's through a TV and had to manually scale the picture on both of them when I couldn't get the TV's auto scaling to work properly.