Bonds is usually his own worst enemy when he opens his mouth. He's an intelligent guy, that much is obvious, but he can get wrapped up in his emotions and not think things through before speaking, which explains his often contradictory statements. That quip back at Costas was pretty priceless, though.
As a lifelong Giants fan and someone who has watched Barry Bonds play since his high school days, I think most casual observers just don't have enough data points to judge his physical development. Don't know how many of you were old enough to see Bobby Bonds play, but if I were to pick one ballplayer from the past 50 years as the ultimate baseball player physically, it would be Bobby Bonds Sr. The guy was built like the proverbial brickhouse, and he didn't even have to work at it! Quite the contrary: he was squandering his "next Willie Mays" physical gifts on drink, drugs, and cigarettes, which drove him out of the game prematurely in 1982. Barry was very close to his dad and saw firsthand both the waste of his talent and the excoriation he regularly got from the media (and some may even recall that his Godfather, Willie Mays, was not exactly a media darling during his playing days, either). Both of those factors are IMO his driving motivations even today.
Barry was no string-bean back in high school. He was already a man amongst boys. He slowly but surely filled out over his major league career, but I recall seeing a Giants game early in 1996 or so and really noticing a dramatic change in his physique then. It was kind of surreal seeing the guns on him at that point.
In 1998, Joe Carter had a brief cup of coffee with the Giants at the tail end of his career. Giants fans roundly derided the acquisition of such an obviously washed-up player, but he did have a significant impact on the Giants franchise. Why? He introduced Bonds to Canadian Maple bats.
In 1998-2000, Bonds' swing and overall approach at the plate was changing. The swing was lengthening a bit and developing more of an uppercut and he swapped out the old toothpick for the big maple bat, but he was still working out his new approach (and was injured for much of 1999). It all came together in 2001.
Harken back to Bonds' approach at the plate from the late 80s through the mid 90s. He used one of the smallest, lightest bats in the game, and he choked-up on the thing! He had an extremely compact, lightning quick, level swing, and he was primarily a line drive hitter, many of which were scalded enough to get over the fence. Sure, he would still hit a consistent 35-45 HR in a season, but his approach through those years sacrificed a lot of power. If he'd used a bigger bat and had more of an uppercut swing like he has the past 7-8 years, he'd be well over 800 HR by now.
Honestly, I've been worn down by the steady drumbeat against Bonds and wouldn't really be too surprised if he did cheat. But I still think the figures in the case against him don't add up -- indictments for perjury and/or tax evasion would change my mind in a heartbeat, but perjury seems like it will be too tough to prove and Kimberly Bell's credibility seems to be shrinking with every passing day, but the door is still open.
I think columnist Bruce Jenkins, who positively loathes Bonds, got it right in a column from this week: if nothing becomes of these investigations, the "taint" around Bonds will fade away and he will be universally recognized as one of the two or three greatest players ever.