Just had a look and this is what Rockstar have said about them:
Rockstar has explained that all three games also feature quality-of-life improvements such as updated controls inspired by GTA 5, "improvements to targeting and lock-on aiming, updated Weapon and Radio Station Wheels, updated Mini-Maps with enhanced navigation allowing players to set waypoints to destinations, updated Achievements, Trophies, and more." You'll also be able to immediately restart a failed mission, cutting out major points of frustration from the originals.”