I can echo this, while doing its job most of the time, Omnisharp has been one of the least stable parts of my VS Code C# experience (the least stable as usual being anything relating to Unity ;) ).

Issues like runaway compiler threads, slow response times, OmniSharp frequently losing the mono-path and requires restart (this is some config issue and interaction with Unity, but could have been handled automatically).

It's sensible to improve the C# experience on VS Code, but not saying the way MS is doing it here is the best way.