Keith of F1Fanatic has as usual come up with an excellent analysis of the current team and drivers pecking order in F1 for this season so far. It seems the indications during winter testing has some accuracy to it although everybody says that we cannot take any times from testing seriously.
From winter testing, everybody knows or have guessed that the top 4 teams would be Red Bull, McLaren, Ferrari and Mercedes - not necessarily in that order. And they were right, so winter times does have some bearing, it's an indicator. And we have been proven right. So heading to Spain, we have the top 4 teams - Red Bull, McLaren, Ferrari and Mercedes - hot on each other's heels with massive development waiting to make an impact.
So here are the links to Keith's analysis:
The pecking order as the teams ready their Barcelona performance upgrades
Jenson Button form guide
Lewis Hamilton form guide
On the side, it's worth mentioning that although it seems that Button has out qualified and outraced Lewis so far, he has been doing it on making the right calls. But Lewis has been far superior when it comes to pace and overtaking. Lewis has done 32 overtaking maneuvers so far compared to Jensen's 7.
So I would say that on a one-on-one basis on a free track and nobody around, Lewis beat the crap out of Jensen, hands down.