On the surface it looks like D&D but it's not. Modify D&D is hazardous and requires work. The AGE system is a toolbox. Pick and choose. Just ignore the level upgrades that don't work for you and use Gritty Mode.
- Focuses (skills) stack with abilities. You can't invest in the same Focus two levels in a row.
- Talents (professional training) have three levels (novice, expert, master).
- A specialization is gained at level 4. It also has three levels.
The Companion book offers a levelling up method that opens up the whole system to you. Just pick and choose how you want the PCs to progress. Each time they would gain an upgrade (vertical) give them a lateral (horizontal) choice instead.
Note that Social encounters and Exploration encounters are very well defined in this game. There are chase rules, hazard rules (fire in a building). There is a section on Reputation, honorific, contacts, membership in groups (gangs). Relationship bonds are also well defined. The Companion book has a ten page section on how to incorporate and use Organizations in your campaign.
If you want to know more download the free QSR of Modern AGE. It includes a mission and pre-gen characters. It will give you a good over view of the system:
DriveThruRPG
www.drivethrurpg.com
One more question, as far as adding options in the future. I'm guessing that Fantasy AGE has a big focus on magic in the world, do the two work together easily, or would it take considerable modding to plug fantasy stuff into Modern AGE? I intend to have a fair bit of variety in spells that can be found, since it will be coming from a variety of sources, and want as many options as I can get.