My understanding is that is largely due to limitations of Visual Studio extensions, not due to performance issues with Reshaper specifically.

I have both VS 2019 and Rider installed, Rider is my main IDE and VS I use pretty much only for SQL Server projects.

Riders ability to seamlessly handle git branch changes vs Visual Studio choking horribly on the same is worth the (very affordable) price alone.

I was a VS+R# user for many years, but switched to Rider a few years back - I absolutely love it!

I was really sick of the constant slow-downs and occasional crashes in VS. Rider absolutely flies by comparison, and has been rock solid - I've only ever had a crash while testing out an EAP version. Oh, and edit-and-continue just works, whereas it's always been really flakey and slow in VS - that alone was a big productivity boost. Another thing is that JetBrains actually listen to what people want, and are constantly adding useful features that people ask for - by comparison, the VS feedback site feels utterly pointless, as Microsoft apparently ignore it, and instead only focus on adding more Azure integration (which BTW is also excellent in Rider!).

The styling takes a bit of getting used to if you've been using Visual Studio for a while, but try a different theme and give it a little time.

Rider is one of my favourite ever bits of software.

Oh, I'm pretty sure we all uninstall Resharper as the first thing we do on a new machine at $WORK :P but VS really does grind to a halt even with ~120 projects in a solution, let alone ~400, whereas the latest EAP Rider is good to go in within minutes. Maybe we have an unusually dense dependency graph or something.