Update: There is an issue with the Nvidia drivers that kept buffer storage from being utilized properly on Windows: they do not report the driver version. Since the Linux version of the driver reports its version correctly, the Dolphin devs assumed that the nvidia drivers would report it and used a version check to make sure ARB_buffer_storage was only utilized on drivers that actually support it. Because of this issue, even the latest drivers that support the function failed the version check and Dolphin didn't use buffer_storage on Windows. And thanks to an unrelated bug discovered later, the lack of buffer_storage wasn't detected in the initial testing. As of 4.0-722 the version check was removed and buffer storage is confirmed to be working correctly.
Unfortunately, that version check was there for a reason. Some driver versions tell Dolphin that they support buffer_storage, but actually don't. Any user caught in that situation will encounter a blackscreen. If you do, update your drivers.
One of the constant struggles in modern emulation is the battle between performance and accuracy. Throughout Dolphin's history, developers have added various tricks to get more performance out of computers - one of them being the Vertex Streaming Hack, formerly known as Hacked Buffer Upload. It drastically improves OpenGL performance on Nvidia GPUs. However, as of 4.0-615, the Vertex Streaming Hack has been removed from Dolphin.