Ear cartilage is higly specialized, thin deformable cartilage that is used all the time for nasal surgery, mainly in reconstruction, and primarily in areas where fine-tuning needs to be performed. Warping occurs as the scars heal and contract over time...these forces can uncontrollably deform the cartilage and twist the results.
I am a big fan of ear cartilage in very specific circumstances or when other sources are not readily available, i.e. septal cartilage from inside the nose. Septal cartilage is very rigid and resists deformation over time better than ear cartilage. Again, both are great options in very specific indications. For tip elevation and a tip-plasty, I typically use septal cartilage if it is available. If it is not and we need structurally rigid support, I then move to rib cartilage.
Make sure you excert all your options and see as many Board Certified surgeons as you can to gather as much information as you can with regard to your particular case.
I hope this helps!