I have had ZERO problems with Atlas shingles,,,,,,Zilch,,,nadda....Around 3,400sq and nothing.And since you are asking I will explain my opinion.
Atlas offers a 35 year shingle.Will they last the full 35 ? Probably not.Will a GAF,Tamko,Certainteed or O.C ?,,chances are no.And here is my reasoning,,
A climate of extreme heat or constant sub zero temps with heavy snow and ice put your roof through hell.Throw in hail,damaging winds,tornado's and hurricanes added by normal wear then all of these things impact the longevity of a roof system.
I have to be completely honest.I believe the 3 tabs from back in the day were the best as far as life expectancy.I have done re roofs where the homeowners swear up and down that the roof has been on the house for 20+ years.In my honest opinion the shingles today don't measure up IMHO.
But no one finds this as a surprise either, but even on a day that is pleasant to us,,65*-70* your roof is still taking a beating regardless.
Now the installation factor,,,If you had 2 separate contractors and contractor A installed a 20yr classic O.C shingle 100% to spec by the manufacture,and contractor B installed a 35yr Atlas with an improper nail pattern along with other "Typical" rookie mistakes then who would have the best chances for the material to live the longest life? Obviously contractor A.
Another thing to greatly reduce a roof's life expectancy is inadequate ventilation as well as your attic insulation.So 5 things (so far) affect your roofs life expectancy.
5.Tear off versus a recover.(Tear-off is necessary for max life)
Which of the 5 are the most important? The contractors ability to install according to manufacture specifications.And here is why;
1.The contractor will know what materials best fit your needs and wants.
2.The contractor will also know how to install the product to reach the maximum amount of material life to also fit your needs.
3.The contractor will know how much ventilation is needed to best fit the ventilation needs for your structure.
4.The contractor will also take notice of the amount of insulation you have and compare it to what your attic needs.
5.The contractor will also detour you from a recover since they greatly reduce lifespan.
And did you know that improper ventilation or no ventilation will greatly reduce your material warranties by more than 1/2?
Did you also know that EVEN if you have a material manufacture dead to rights for a product defect more times than not they (manufacture) can side step coverage if the materials are not installed to spec's?
Sounds to me like a professional contractor should be your first and foremost task.After you find him/her your well on your way and material selection will fall into place.
I am sure this is more than what you asked initially,,sorry,,I get carried away sometimes.