Dhoni is a average keeper at best...
Dhoni is far better than Prior Dave.
2007 in England Dhoni's keeping was 100 times better than Prior's.
Furthermore, its tougher to keep on low sub continental pitches than more lively English pitches.
With regards to Dhoni's batting, two of his hundreds have been match saving efforts, his 148 vs Pakistan( a far better attack than the current Pakistani attack) and 109 vs Sri Lanka when the Lankans where all over India.
Also its not Dhoni's fault he plays in India is it? He is Indian after all.
Dhoni can score runs again the best sides, unlike Prior who loves to dip his bread vs the ordinary West Indies side.