I imagine you have to spend half your time looking things up.
VS's built in shortcut ctrl-, does more or less what R#'s "symbol search" does.
In general, to be honest, R# feels smarter (remember, I’m biased and likely work to the strengths of R#).
But another aspect here is that with R#, I rarely have to leave my current context, pretty much everything is available immediately from where I am. With R#, this shows up in the middle of the screen, with VS, that is all the way at the right, so I need to move my eyes to track it. Reference search in R# shows , and with VS, it shows in a window in the bottom.
Please note that this is very much an unbiased review.
Update I have tried R# & VS 2017 for a couple of days now, and I can tell that aside from the project open times (which are atrocious with R#), I’m not seeing anything major performance wise.
That said, project open time are also “switch between branches”, and that is a major PITA.
It seems to happen with Nu Get, or when trying to use the Test Explorer and a few times when I was trying to edit code while the solution was compiling.
Without any meaningful order, here are the things that I really felt the lack of.