The first few races, RBR were definitely quicker. As the season has progressed Ferrari and McLaren have moved forward on race pace.
In Canada, McLaren were (race pace) quicker and I suspect that Ferrari would also have been faster.
In Monaco, we also saw Alonso and Button, both faster than Vettel, at the end of the GP. Once again, Ferrari and McLaren had the quicker car on race day.
Given that RBR had the 3rd fastest car (on race day), in the last race, I would suspect that RBR no longer hold the advantage. Obviously, as you stated there will be some tracks which suit RBR, but for the time being at least, on race day, RBR are not the super dominant team we saw at the start of the season.
The problem with the last 2 races is that Monaco is a drivers circuit, which would've prevented the RBR car from showing its class. And Canada was a such a wet race, again, any car advantage would've been negated (driver skill is more important in wet races).
If I was a betting man though, I would say that on a dry track, RBR is currently the 3rd fastest car on race day.