All things considered, I was more enthusiastic about the Cubs' signing of Aaron Miles when I thought he would be replacing Ronny Cedeno as a spare infielder than when I think of him as a replacement for Mark DeRosa.
Aaron Miles (643 Major League games)
.329 OBP / .364 SLG / 693 OPS / 77 OPS+ / 4.1 Runs Created per Game
Ronny Cedeno (329 games)
.289 OBP / .350 SLG / 639 OPS / 62 OPS+ / 3.2 Runs Created per Game
Mark DeRosa (893 games)
.348 OBP / .422 SLG / 780 OPS / 97 OPS+ / 5.2 Runs Created per Game
It has been pointed out that last year DeRosa set career highs for HR (21 vs. previous high of 13), RBI (87 vs. previous high of 74), OBP (.376 vs. previous high of 371), and OPS (857 vs. previous high of 813). It is also true that as DeRo closes in on his 34th birthday, it's likely he will see some regression from those best-ever numbers. But '08 also saw Miles set career highs in several categories, including the ever important on-base percentage, where Miles's .355 mark was well above his previous career best of .329.
Ironically, .329 is also the lifetime on-base percentage of the guy Miles may replace as Cubs leadoff man—Alfonso Soriano.