Firm, but so very comfortable! I was skeptical about how firm this mattress would be due to some of the reviews. But I was pleasantly surprised! It's the perfect amount of firmness, yet still very comfortable.  
The mattress arrived in a tall box. It was hard to believe a 14" king mattress was inside. I removed it from the box and and the transformation began. Within 4 hours it expanded to the full 14"! Its the most comfortable mattress I have ever slept on. I highly recommend it!