Hello 
I remember in 2018.3, a feature was a much faster scene saving speed. Now in 2019.1, this seems to have slowed down majorly. It now takes minutes to save my scenes, even when just 8 scenes are open. Before it would take around 4 seconds or so.
Josh
I am also experiencing the same slowdown, whenever the scene has to serialize data, recompile, or playing in the editor. Also spikes during play. All in all, ~4-5 times slower than 2018.3.
Have not noticed any slow downs myself. Seems the same for me.
I have not been able to replicate this issue anymore, so I suppose this thread should be locked