well i cant post a screenshot but just look for games like call of duty, halo or games made with the source engine, these engines are based off the quake engine and all use blocks in some way [may be modified to some extent but the idea remains the same]

meaning, use blocks for your main architecture[basic level layout] and then use models to add detail objects, thats how we approach it, though the reason to use blocks over models depends on your project, for us we needed shadowmapping and blocks was the easiest way