I don't know about 2, but one of the main reasons I returned my 2018 13" for a 15" was that the 13" was struggling to run my 32" LG 4k display. The overall smoothness of the machine would drop and when playing 4k youtube videos in fullscreen the videos seemed to be running at a really low frame rate, much lower than the videos original fps. With the 15" due to the dGPU I have not had such issues and everything is running as intended with the same monitor.
I don't know about 2, but one of the main reasons I returned my 2018 13" for a 15" was that the 13" was struggling to run my 32" LG 4k display. The overall smoothness of the machine would drop and when playing 4k youtube videos in fullscreen the videos seemed to be running at a really low frame rate, much lower than the videos original fps. With the 15" due to the dGPU I have not had such issues and everything is running as intended with the same monitor.
This. I returned my 2018 MacBook Pro. Had it connected to a 5k display and more often than not, under decent load, the fans would constantly keep spinning and get real noisy.
Going back to my 15" 2017, the machine runs really smoothly with the fans never almost ever running under the same load. Can't bring myself to shell out 4k for a 2018 15" when I have my 2017 15" that works perfectly for my needs. I do have a 2017 12" MacBook which is my main portable machine so my 15" almost always stays docked to the LG 5k display at home.
Personally I think, Apple tried to squeeze more power from the current Mac's by increasing the cores, but the thing gets so hot that it cannot sustain it or the fans have to work overtime.
Im glad im not the only one. I had no reason to lie and was literally using a 2018 15 and 13 side by side doing numerous stress tests and daily work flow testing to see which machine would work best for me. The 13" clearly was lagging and sluggish when connected to my 32" 4k display. Like I stated earlier, framrates in 4k youtube videos were horrendous to the point where I would have to play them back at 1080 and window size to get it to perform decently. People are quick to discredit your experiences just because they haven't experienced the same thing on completely different and older machines.
Well that's super ******. Why does apple say it can support external displays when it can't?