The Power were definitely an intriguing team, but not necessarily the system's most prospect-packed. A number of its hitters had strange seasons in which they hit homers but posted very low batting averages, and what was supposed to be a very deep, prospect-heavy pitching staff turned out not to be when a number of hurlers went down with injuries.
The Power had about an average offense, but they took a weird path to get there. In a 14-team league, the Power ranked 12th in batting average, but second in homers. This happened thanks mostly to Evan Chambers (12 homers, .239 average); Rogelios Noris (15 homers, .236); Aaron Baker (18, .253); Jesus Brito (.197, 11); and Kyle Morgan (.203, 11). The Power also finished third in the league in walks.
This is, of course, better than a bunch of hitters who are just completely impotent, and these guys are young and have time to learn. Also, fortunately, this pattern exists only with the Power and not throughout the organization. But the overwhelming impression I get with players who do this is that they're going to struggle to get to the majors. You want prospects to have a wide range of hitting skills, but if they're going to be deficient in one, I'd rather it be walks or power than average.
Take Starling Marte, for example. No one ever complains that he drew only 13 walks against 248 at bats this year, because walks and power are old-player skills that can show up later. Batting average generally doesn't, and if a player hits .239 with power and walks in Class A, he's often going to sink at the higher levels, as pitchers throw more strikes and make fewer crushable mistakes. I've written about this a bunch with regard to Chambers, but it applies to the other guys too. There are occasional examples of players who hit for low averages in the minors and go on to have pretty good careers - Rob Deer and (as Vlad pointed out) Mickey Tettleton are two, and Mike Napoli kind of qualifies as a third. But many players who hit for power and walks but have low batting averages in the majors hit for decent averages in the minors - see, for example, Carlos Pena, Mark Reynolds and Adam Dunn.
Anyway, the upshot of all this for the Power was that they had a bunch of guys who really looked like hitters - the ball really jumps off the bats of Chambers and Brito, for example - but they didn't actually hit all that well. The closest thing they had to a well-rounded hitting prospect was Jarek Cunningham, who hit .258/.309/.436 in his first full pro season, although infielder Elevys Gonzalez, who arrived partway through the year and hit .275/.354/.424, also bears watching. (Those are good numbers for a 20-year-old.) For all the homers the team's prospects hit, much of the offense was provided by two likely organizational players, Jose Hernandez and David Rubinstein.
The Power's pitching staff was supposed to be packed with young prospects, but that didn't happen, as many of its likely players (such as Victor Black, Quinton Miller and Jeffrey Inman) ended up sidelined with injuries. (Four of those guys, Miller, Black, Brett Lorin and Hunter Strickland, each pitched a handful of starts, and none were particularly successful.) The Power thus gave a ton of innings to non-prospects like Jason Erickson and Brandon Holden.
Still, one clear prospect, Nate Baker, pitched well, nearly threw a no-hitter and earned a promotion to Bradenton. A quick start there in 2011 could get him to Altoona fairly quickly - as a fifth-round pick and a college lefty, the Pirates will probably promote Baker a little more aggressively than usual.
The Power's other two main starting pitchers, Phillip Irwin and Kyle McPherson, put up great numbers, but we'll have to see what that might mean. Irwin came from a major-college program (Ole Miss, where he pitched with Baker) and doesn't have outstanding stuff. That type of pitcher often destroys the lower levels but will struggle after reaching Class AA or so.
As for McPherson, the Pirates have moved him through the system very slowly, suggesting that they don't think much of him. He took a nice step forward this year, though, striking out more than a batter an inning. The Bucs moved him up to Bradenton at the end of the season and he pitched well in two outings there. He relies heavily on his changeup, however, which might be the sort of pitch that higher-level hitters find less confusing than Class A batters do. He also allows a ton of fly balls, which might cause problems against hitters with more power (every team in the South Atlantic League had a slugging percentage in the .300s).
The only other pitcher who pitched more than a few outings with the Power who warrants a mention, at this point, is Eliecer Navarro, a small lefty who has consistently put up good numbers in the Dominican and in the U.S. minors. Again, though, a small lefty without a big fastball is the sort of pitcher whose numbers probably shouldn't be taken at face value - he may struggle as he moves up.