The good thing about learning C++ from C#, is that they look very similar. The bad thing is that they look very similar. You might feel I'm not making sense, but I'm trying to make a point. When I learned C++ coming from Java (I also know C#), I felt it was easy because their syntax are very alike, so that let me to made presumptions in which it made it harder to find the differences (very important differences) between the two.
While you can't go wrong on reading a 1500 C++ book, it might not be an optimal solution. You already have a programmer's brain, so you shouldn't start at the beginning of the line.
My First suggestion is to read tutorials highlighting the differences between the two:
Make sure you learn the differences, because at this point, you might be thinking in C# but coding in C++.
My second suggestion is then to read intermediate books highlighting the gotchas, the pitfalls and tricks. Scott Meyers' effective series, Stephen C. Dewhurst 2 books : gotchas and intermediate essential. After that, you want to look for Herb Sutter and Andrei Alexandrescu literature and the CPL book as well. Also, keep a copy of the standard.
My last two coins about learning C++, At the beginning of my C++ journey, I felt that I knew almost everything about it. Now that I have read many C++ books and C++ coding for the past two years, I feel that I know so little of C++. See the more you will know about C++, the more you realize how little you know about it. The reason that I'm telling you this is because a lot people underestimate C++. They usually don't pass the basics and don't go beyond their comfort zone and since the syntax might resemble their previous language, the easy-to-learn-C++ myth is born. So don't be me, treat C++ with a lot respect.