All-Wheel Drive cars have more traction (naturally) and can therefore attain higher speeds in a shorter space, but require very precise driving to extract the most from them. Rear-Wheel Drive is quite challenging, requiring a lot of throttle control and very smooth inputs. It’s incredibly fun and sideways, and the ability to successfully handle a Rear-Wheel Drive car through slippery rally conditions is quite rewarding. Both are incredibly fun, and will increase your driving ability and car control beyond what’s possible on a track.
Most of the works drivers of the 1950s were amateurs, paid little or nothing, reimbursed their expenses and given bonuses for winning (although there were certainly exceptions, such as the Grand Prix drivers who were brought in for some events). Then in 1960 came arguably the first rallying superstar (and one of the first to be paid to rally full-time), Sweden's Erik Carlsson, driving for Saab.