Dont know about best, but the guys game sense is very good.
Few years back when Rizwan was near the edge of getting selected for the Pakistan team, the Peshawar Panthers on Faysel Bank t20 was on the rise. PTI had won from KPK, and anything good that happened in KPK and Peshawar was boosted alot. Similarly, when Peshawar region and Peshawar panthers were doing well in cricket, alot of the guys got the attention of the people. Few players that were being noticed were Rizwan, Rifatullah, Israrullah, Sahibzada Farhan, Imran Khan (the medium pacer) and Iftikhar Ahmad.
There was an innings that was played in the final where Peshawar was struggling abit and Riffatullah and Rizwan were batting together. Rifatullah, uptil that point, had years of domestic experience. During that match, he tried to play some wild shots and couldn't connect ( i think they were chasing), and than Rizwan went up to him and said that he needs to relax abit and take the match till the end. Thus, they started to rotate the strike and ended up chasing a high total.
Rafatullah even praised Rizwan during the post match conference. His game sense was always very good.
He is the best ever wicket keeper batsman produced by Pakistan. THe likes of Moin, Rashid or even Wasim Bari are no where near this guy.