Grit, fitness, Stmama and determination YK has we have not seen in any of our greats. None of them were as disciplined and fit as he is. Inzi and MoYo were horrible runners between wickets, so many runouts in test ( Ironically I am mentioning this when YK and Azhar had terrible running between the wickets day).
As far as playing in testing conditions is concerned, nobody has even made double ton in green and wet conditions we saw last month in NZ or on a rank trunners India made for SA, I am talking about any batsmen including Bradman, it's not humanly possible. Most if not all big 100s are made when conditions get easier.
Also, none of our greats were good against moving ball, Sami knows his off stump better than any of our greats, there is a reason they all played in middle order. It's not like one was so much better than other.
Before calling him FTB, remember this he is the king of 4th innings, batting is hardest on 5th day, even in Asia, and he has passed that test not just against Pakistani greats but all greats with flying colors. Let's cherrish for what he is.
His main problem is that he is too jitter and out of sort in first 40/50 balls of the innings, well everybody does but he has trouble more than others. But once he get through that, he develops his innings very well, he grows up within an innings probably better than anybody else, that's why he makes so many daddy 100s. In modern era where many top batsmen struggle against spin, he is one the best in the business, you cannot shrugged that off as nothing special, it's not a fluke, it's a dam good skill!!!
He is definitely Pakistani Great and modern day test great, weather the Greatest Pakistani, that debate one can never settle.