The Cardinals have the #1 offense in the NL. So their goal of improving the offense has been pretty successful. This is of course due in large part to signing Lance Berkman (not Ryan Theriot). Unfortunately the Brewers have the #2 offense but have a better starting rotation. Still it's fun to note that the Cards .331 team wOBA > Brewers' .325 wOBA. (which is oddly enough tied with the Mets). This can be seen in the Cards' better on base percentage, which results in more RBI's. Slugging-wise, the Brewers and Cardinals are equal so far.
But this year is all about pitching. The Phillies offense, while not horrible, is just not that scary. Their pitching however is absolutely deadly for opposing offenses. Simply put, they have the best pitching in major league baseball, and it's not even that close. 2nd in the majors are the Giants, followed by the Braves, White Sox, Padres and Brewers (going by FIP). The Cardinals aren't doing too bad at 13th in the major leagues.
Perhaps an area where the Brewers far out-distance the Cardinals is in fielding. The Cards have been pretty terrible by UZR in '11. The Brewcrew however are a top 10 team in the majors by UZR. Only the Braves, Astros, and Orioles are worse at fielding (of course, UZR is not infallible but I think this shows that it's been a liability for the team. thanks, ryan theriot).
Holliday and Berkman continue to lead the team on offense. An interesting observation (imo) is that Holliday leads the team in wOBA, and Berkman leads in OPS. Berk is showing more power though, and Big Matt is getting on base at a .419 clip. Albert has been rather unlucky this year: .259 BABIP! This leaves Craig's rate stats higher than Pujols, so he is third best in wOBA (however, it is fueled by an insanely high .364 BABIP). Pujols does lead Craig in OPS though, and obviously in WAR. David Freese and Jon Jay round out the rest of the good Cardinal hitters. Yadi is having a great offensive year with a .325 wOBA.
Jaime Garcia is this year's staff ace, despite some declining starts the last few times out: 3.11 FIP. Chris Carpenter is quietly having another great season at 3.13 FIP. Kyle Lohse has also been good: 3.85 FIP. One last note: Jason Motte has been crazy good, and a lock in the bullpen with a 2.43 FIP and a 1.93 ERA... making him one of the best relievers in the major leagues, and even better than Mariano Rivera in FIP.