The Reds just picked up one of the top pitchers in baseball!
I'm so out of it I don't think I can give a detailed analysis of this trade in my typical style. I'm not entirely convinced that stuff is meaningful anymore anyway. So here's my very brief opinion:
What they gave up: Grandal is a nice talent to give up, but the rest were in my opinion fairly marginal prospects. Boxberger's a relief pitcher, so whatever. Volquez is now someone else's problem, and Alonso is a low defense, low/moderate power 1B. Obviously the Padres (and a lot of other people) disagree with me, or they wouldn't have given up Latos.
What the Reds got in return: a top notch pitcher. Cameron breaks it down well. But even without PETCO, Latos should be successful. He is a power pitcher, with a fairly hard four-seamer for a starting pitcher (93 mph) and a badass slider (23% whiff % vs. 14% MLB average), as well as a two-seamer, curve, and change. It's pretty freaking exciting to see the Reds making a move like this after what seems like YEARS since they went all in on a trade. This is better than the Marcum deal, and on par with the Greinke deal of last offseason in terms of the quality of the pitcher they acquired.
And then there's the contract. He has two years of service time. This means that the Reds control him for FOUR MORE SEASONS (I think). This is enormous. Even if he walks at the end of that time, the deal is fabulous for the Reds. A player like this is extremely hard to acquire, so major kudos to the Reds for getting it done. This is arguably the most valuable pitcher acquisition in recent years.