It is definitly not a walk in the park but it is one of the easier concerti in the repertoire.
As for good Mozart Concerti, I think no one disagrees that his latests ones are of much better quality. The 20th, the 23rd are both wonderful, but souless to me compared to the more romantic/contemporary compositions, such as the Rachmaninoff's, or the Prokofiev.
But given the idea of the limitation of getting a huge orchestra, or the fact that pianos didn't exist back then, I think he makes a pretty good job.