The Cubs traded Sean Marshall to the Reds for Travis Wood, Dave Sappelt and Ronald Torreyes.
Marshall had a 2.5 WAR in 2011, and a 1.7 WAR average over the past 3 years. This is a bargain at a 3.1 million dollar salary for 2012, but he is a free agent afterwards. In 2011, he had a -3.75 PE, and -4.15 Adjusted PE. For his career, his PE is .33. In 2011 he pitched like a closer-type, but for his career, he has not very good reliever numbers. That is because earlier in his career, he was used many times as a starter. The Reds are probably not going to use him in this role, so it makes sense just to look at 2010 and 2011, the two years where he only pitched as a reliever. Those two years, he put up FIP - of 55 and 46, and SIERA's of 2.34 and 2.20. This is much better than their previous 9th inning man, Francisco Cordero, and is slightly better than Jonathan Papelbon and Ryan Madson.
Wood has a 1.5 WAR in 208.2 innings, which is about a full season. Fangraphs actually gives him a 3.3 WAR, as his PE is .99, but his adjusted PE is .56, virtually all as a starter. This is pretty solid. His FIP - is 94 with a SIERA of 4.22. He is a flyball pitcher, but he hasn't been bitten by the longball. He has given up a lot of line drives, but seems to be a pretty average starting pitcher that doesn't cost anything and is under club control for quite a while.
Ronald Torreyes is 19, and has never played above A ball. However, he has been pretty good, earning a .419 OBP and .935 OPS. He doesn't walk much, at just 5.3%, and he isn't a home run hitter.
Dave Sappelt has played in 38 games in MLB, so it is more helpful to look at his minor league statistics. He has 451 PA in AAA, so we should look there. There he had a .374 OBP, .838 OPS, and 3.16 Simple WAR. This translates to a .328 OBP and 1.67 Simple WAR. He is below average at Center Field however.
It appears to me that the Cubs won this trade. Even though the Reds got an under the radar elite relief pitcher, they gave up a cheap average starter, and a center fielder that is a good hitter and major league ready.