Readability Over Time: Pitman Vs Gregg

Hi Guys,
    I have heard online many times (in the rare odd places you can actually find stuff about shorthand!) that people tend to believe for some reason that of the two systems of highest popularity, Gregg and Pitman, Pitman is superior for readability.
    They often say that many reporters back in the day that used pitman were able to read back their notes they had made even years ago and read them and all their brief forms with ease. They say that Gregg is incredibly fast but that in comparison, the notes take considerable time to translate if it's been a while.
    However, in some old books written in the thirties and forties about reporting shorthand, they mention this and say that the only time that any shorthand writer will have such trouble will be if they have not mastered theory and have made quick and hastily made outlines and phrases that were not ever impressed on the memory through practice.
In my own experience I can still read stuff I wrote when I was first started three months ago just fine even though it was pretty ugly, but I'd love to know your experience with much older notes or even if the Gregg ever gets hard to read after time. Please let me know your opinion