Okay, yes from his good qualifying pace, qualifying in the top 10 on several occasions and he only scored once. However when you look back on the final races of the season Senna was more unlucky than anything. On several occasions, such as Abu Dhabi he had KERs failures and the like. As well as what I feel poor decisions about penalties such as in Brazil with Schumacher which was in my opinion just a racing incident.
You say ‘rusty’ but just look at the start of the Belgium Grand Prix. He was rusty there due to the fact that he went charging into the first corner with race distance fuel and cold brakes. Although from what I remember he had problems in practice which was wet, he crashed. So he didn’t get any race distance fuel running.
He isn’t the best driver I’d rather see Alguersuari in the Williams this coming season, but I rate him with the similar speed of Sutil.