I've installed these files from their site:
- Qt 5.3.1 for Windows 64-bit (VS 2013, OpenGL, 571 MB)
- Visual Studio Add-in 1.2.3 for Qt5
After that, I tried to follow this simple tutorial but when I try to actually build the generated project it fails at linking saying "error LNK1112: module machine type 'X86' conflicts with target machine type 'x64'". I did exactly as the guy in the tutorial says, changed the Target Machine to Machine64 and set the platform to be x64. If I try to build it as Win32, the following message box pops up.:

I've set the "Qt Version" path to C:\Qt\Qt5.3.1\5.3\msvc2013_64_opengl. Maybe that's what's bothering the linker? On a side note, I have three projects in the solution - two of them are x86 and the Qt one is x64.
UPDATE: Everything works just fine in Qt Creator.
UPDATE 2: Qt project's vcxproj.user file:
<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="12.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
<PropertyGroup>
<ShowAllFiles>true</ShowAllFiles>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|Win32'">
<QTDIR>C:\Qt\Qt5.3.1\5.3\msvc2013_64_opengl</QTDIR>
<LocalDebuggerEnvironment>PATH=$(QTDIR)\bin%3b$(PATH)</LocalDebuggerEnvironment>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|Win32'">
<QTDIR>C:\Qt\Qt5.3.1\5.3\msvc2013_64_opengl</QTDIR>
<LocalDebuggerEnvironment>PATH=$(QTDIR)\bin%3b$(PATH)</LocalDebuggerEnvironment>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'">
<LocalDebuggerEnvironment>PATH="$(QTDIR)\bin%3b$(PATH)</LocalDebuggerEnvironment>
<QTDIR>C:\Qt\Qt5.3.1\5.3\msvc2013_64_opengl</QTDIR>
</PropertyGroup>
<PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'">
<LocalDebuggerEnvironment>PATH="$(QTDIR)\bin%3b$(PATH)</LocalDebuggerEnvironment>
<QTDIR>C:\Qt\Qt5.3.1\5.3\msvc2013_64_opengl</QTDIR>
</PropertyGroup>
</Project>
PATH="$(QTDIR)\bin%3b$(PATH). There is an opening quaotation mark which is not closed. - UmNyobe