So far, it appears Brady is winning the "who was a bigger influence on the Patriots' success?" argument.
Read up or last years thread. Tampa had a very good team with a horrible QB last year. Any QB you'd rank in the top 30 and the Bucs were going to win 10-12 games this year. Brady is currently 2-2, average, against teams with winning records. Tampa has 3 games left against teams with winning records.
Last year Winston was sacked 47 times (mostly from holding the ball forever), 30 Int, 12 fumbles, with 5 lost. That's 89 drives killed. Brady is on pace for 20/8/8/2 or 38 drives killed. I picked out David Carr as an average QB on an average team and his numbers project out to 26/4/14/8. I'd bet Tampa would be 6-2 with Carr at QB also.
Not taking anything from Brady's career but the record in Tampa this year has much more to do with the quality of the team than the quality of the QB.