Balanced is the word that best describes the 2008 Cubs. 

The 2008 Cubs won 97 games, with winning records in every division (except interleague).  They scored more runs than anyone in the National League, 56 more than the next best teams.  Only the Texas Rangers scored more runs in all baseball.  Similarly, they were second best in runs allowed (second to the Dodgers of all teams) in the NL, tied for second in all of the majors.  This was a good team on both sides of the ball, the best team many of us have ever seen.

Breaking down the numbers a little more...

The Cubs were one of four NL teams to have winning records on the road.

They went 24-22 in 1 run games.

Their batting splits are astounding in how flat they are.  The Cubs hit .274/.350/.443  v. RHP and .288/.366/.442  v. LHP.  There was little difference between their splits in the first and second halves, little difference between hitting with runners in scoring position or no one on, between fly ball pitchers and ground ball pitchers.  The only significant split was the Cubs' showing v. power pitchers, where they took nearly a .100 pt OPS hit.

Their pitching splits show a lot of the same stability.  At home and away, first and second half, day or night - it was the same Cub team.  There was a significant split in the Cubs pitchers v. RHB and LHB, to be expected when 4/5 of your starters are RH and Carmen Pignatellio set the storyline for LH relief on day one.

Looking at that review, the Cubs obviously are going to want to dig deeper into individual numbers, but it seems like there is only one glaring place the Cubs MUST improve in terms of regular season performance.  The Cubs are going to want to have at least 2 viable left-handed relievers who can get left-handed batters out.

What about a left-handed bat?  The Cubs have been seeking a left-handed slugger since Jeromy Burnitz.  But do they really need one?  Before you say, "No," reflect that Jim Edmonds was a pretty big left-handed slugger in these 2008 numbers, and he's not likely to give that performance again. That said, the Cubs may have to watch about going too far in acquiring left-handedness.

What about, finally, the difference between this team's performance in the regular sesaon and the post-season?  The Cubs played well all season long against the better teams.  The one split that stands out is their performance against AL teams, who really bullied our pitchers.  Also, throughout the regular season, the Cubs hitters did fine in "Clutch" situations like tie games and late in close games.