fangraphs.com has some excellent defensive statistics (that's where you find UZR, ERA - FIP and defensive run values included in WAR statistics. You can click around the fangraphs database and find all kinds of interesting info.
Also check out thehardballtimes.com for defensive win share data and RZR metrics (including out of zone (OOZ) plays)
The problems with traditional fielding metrics are documented and numerous.
There are 27 outs in a game...that is true whether your defense is awsome or crappy. Which means there is actually in INVERSE relationship (albeit slight) between team range factor and team quality (because bad teams tend to have slightly lower K rates on average so they get more defensive outs)
F% makes the Mariners of 2009 look horrible because they were getting to many balls that other teams flat out missed (and turned into hits)
In fact, even traditional field-level scouting has a tendency not to be reliable for judging defense because it's often the best fielders who make all plays look routine, while the average fielders get to some balls but have to make spectacular plays to do it. Which is why you saw Yuniesky Betancourt make a lot of highlight-reel-looking plays even while suckig horribly on defense.
As it turns out, even simple stats like DER miss a big chunk of the picture in cases like Seattle's. Why? Because when your team strength of OUTFIELD defense, you save not just singles...but XBH as well. Which means DER often misses the total scale of how much defense is helping out the pitching when your run 3 CFers out there all year long, one of whom happens to be the best center fielder in baseball and another of whom happens to be the best right fielder in baseball.
So I wholeheartedly recommend checking out fangraphs and thehardballtimes (and baseball-prospectus.com if you want even a third readily available fielding uberstat). It should give you a good idea as to why some of us think the Mariners are in fine shape to repeat a high level of run prevention despite our pitching being a little shaky.