Comments for and against today's famous evangelists in America can easily be seen and read anywhere on the internet.
Critics telling Mark Driscoll to grow up, John MacArthur to stop criticizing other "christians", etc. have led many others to form their own opinions. Comments grew with less and less conformity to Scriptures.
While it maybe time consuming to debate further theologically, I'd point out one thing which I believe is strong and crucial for discernment:
That Jesus' ministry is not just "attractive" to the 20s-30s youth group. It is acceptable by all age group and without a type preference of any cultural elements.
Consequently, I see a great ministry, a true ministry, one that truly deserves no criticisms from such crowd, when it is conforming to Jesus' "Method".
So if Driscoll's cool stage act or Tim Keller's modern thinker style attract not the seniors, I'd say they really don't deserve the popularity. Because there's that lacking of hardwork for a balanced attraction.
It is better to seek after a truly pious lifestyle that has no shame when dealing with the elders.