The Bennetton was certainly easy for MS to drive. Though we must remember the car was built for him and only him. He put many miles on it in testing and mastered the car. He developed the car and his driving style and the car developed together.
Unfortunately, JJ Lehto, Jos Verstappen, Johnny Herbert, etc were unable to adapt or get anywhere near the performance that MS was able to extract from the machine.
If you look at Senna in 1994. The Williams was clearly a more difficult car to drive, but potentially - once setup correctly and mastered - IMO it was a faster car. Senna only drove it for 3 races and had 3 poles - he went off, while leading in Brazil and San Marino. As the season progressed the Williams car got steadily quicker (or should I say easier to drive) and D.Hill was also improving as a driver, to the point where in Australia, MS was barely able to stay ahead of Hill's Williams. This led to MS going off the track, as he was struggling to stay ahead of the pursuing Hill. When MS knew his race was done, he veered back onto the track, into Hill's Williams damaging its suspension. Both drivers failed to finish and MS won the title by 1 point.
IMO, in 1994, MS/Bennetton were the better package and rightfully won the title - despite the FIA's attempts to stop him. In 1995 of course, MS/Bennetton did it the right way and blew everyone out of the water. It wasnt a Championship as much as it was a demonstration: MS 102pts, Hill 69pts.
I wasnt a big fan of Senna, by my God, he had an insatiable desire to win at any cost. He also had an unshakable belief in his own ability. Hamilton is very similar, but only time will tell if he will become a great.