I think he's done all right. The last three episodes I think it would have perhaps been better lettering Gatiss loose as a double parter for the Daleks and the Angels as a single parter, the first part was pretty boring. Then again when they did that pretty much in Tennant's second season that wasn't as good as it might have been. The first two were pretty good though.
Looking at comparison for the first five stories versus the three Tennant seasons and Ecclestone season I'd say it's no weaker than any of the others. Ecclestone had things like The End of the World, Aliens of London and World War Three which were all right rather than classics. Tennant had some clangers in the early stories in each season like New Earth, Gridlock, School Reunion, Smith and Jones, Partners in Crime. I do wish they'd get Amy to get some more expressions though.