From reading what people have said on this site, you're going to have better success with High Sierra if 1) you have a newer Mac and 2) if you don't have a lot of 3rd-party software.
I see more people have issues with computers around the 2012 timeframe and earlier, mainly in regards to the GPU. If you have 3rd-party software from smaller developers, particularly those that no longer update their software, that can be an issue or if you don't take the time to find out if updates are required for High Sierra.
I recently upgraded my 2014 Mini without major issues mainly because I too need to run the latest Xcode version. I won't be upgrading my other (mainly older) Macs. I had a couple of more unusual apps on the 2014 Mini and in one case it's a 32-bit app and there's a warning about that (the developer says a future version will be ready when the macOS which only supports 64-bit apps is available). For the other app, I don't know if an older version would have worked but the latest version on the Mini required an email to the developer's tech support and additional troubleshooting on my part since the developer had made major infrastructure changes. So those are the types of things that happen with an OS upgrade. Also, I notice that 9.3 (9.4 just recently came out, after I had downloaded 9.3) is a 5.2GB download, the previous version I downloaded, 8.3.2, was 4.5GB.
Performance of Xcode on High Sierra on the 2014 Mini (dual-core) vs. my other computers (quad core about the same CPU frequency) is OK but I've been doing mainly maintenance-type stuff thus far.