This game is great. I like the setting a bunch - the huge amount of official APs really helps for that, of course, by filling in details that even the 500 pages can't contain - but even more than that I like (1) the methodical way the system is laid out, which really gives the sense that the intense playtesting let the author know exactly what rules issues or exceptions needed to be discussed alongside each new rule, and (2) the really elegant marriage of narrative and crunch emphases. RM doesn't try to be all crunch or all story - it's crunchy where it counts, and light and narrative where it doesn't. Don't be surprised if your next campaign after Red Markets strips the zombies away and ends up using the Profit System for some totally different genre. We recently lifted the retirement rules from RM for our Star Wars: Edge of the Empire, for example.
Overall, this game really spoke to me both as a gamer of long experience myself, and as someone who tends to run games for newer players. It's a mature, sharp, conscientious take on gaming and the zombie genre both, and you'll definitely get your money's worth out of this product.